A trickle of misinformation about Labor policy became a torrent on Facebook as the campaign unfolded. A Guardian investigation has tracked the course of the death tax scare, revealing alarming implications for Australian democracy

The Labor MP Meryl Swanson remembers Easter Saturday for two reasons: Chris Bowen came to town to launch her campaign for re-election in the seat of Paterson, and it was the first day she realised people thought Labor would implement a death tax if Bill Shorten won the election.

News about the death tax misinformation reached her via two active branch members, people she describes as older but “digitally literate”. The duo brought copies of material circulating on Facebook to her market stall on that Saturday.

“They were really agitated,” Swanson tells Guardian Australia.

They weren’t the only ones. By Easter, the Labor campaign headquarters in Parramatta was in a process of escalation. Labor candidates were reporting trouble around the country and proliferating fake news was preoccupying the leadership group during their daily conversations.

On 19 April, the national campaign wrote to Facebook protesting against the rapid circulation of death tax claims on the social network over the previous 12 hours, accompanied by what looked like “orchestrated message forwarding” through the messenger service.

Swanson and her colleague Sharon Claydon, who was defending the neighboring electorate of Newcastle, were not hanging around to see what emerged from any complaints. They launched boosted Facebook posts to counter the misinformation. They didn’t cross reference with HQ in Parramatta.

Sharon Claydon, a Labor MP, paid for ads on Facebook to counter the “fake news”, which began on 12 May. Photograph: Facebook

Claydon says her judgment was there was no time to wait. She says by the final fortnight of the campaign, her phone was “running hot” with constituents believing there was a pensioner tax, or an inheritance tax, or a death tax.

One constituent reported to her that he had heard about Labor’s 40% death tax at a barbecue with 50 other people. “My concern was scare campaigns are most effective when they are whispering campaigns – when it becomes barbecue talk. That’s the killer, when you hear this stuff from people you trust. Their opinions matter to you. Campaigns that reach into backyards are the ones that work.”

Claydon says the misinformation caught fire because a lot of voters were unable to differentiate between Labor’s revenue-raising proposals, which were complicated and not well explained. “The death tax got bundled up on the booths with a lot of other tax stories. It’s serious then, because you can’t carve it out”. Swanson says Labor’s controversial franking credits policy “laid the ground for the extrapolations” because it was complicated. She says even though a death tax was a bridge too far, “people were able to build that bridge. It wasn’t true, but that didn’t matter”.

It was a similar story in Sydney, in the multicultural electorate of Bennelong. Brian Owler, a former president of the Australian Medical Association running for Labor in the seat, says: “I was still explaining to people on election day that there was no death tax. It was really hard to convince them. They’d seen it on Facebook. I think it had a big effect.”

The campaign deployed the former prime minister Kevin Rudd to campaign with Owler, and Rudd pushed information out in Mandarin on WeChat to address the fake news directly in the third week of the campaign. “As an individual candidate, you don’t have any direct visibility over how big a problem this is,” Owler says.

“But it felt like a big tide we were pushing against.”

“Mediscare” get square

No one Guardian Australia has spoken to has argued that Labor lost the election because of the death tax falsehood.

No one inside the Labor campaign knows precisely how potent the misinformation was, or how many votes were lost, or whether the fake news can be separated from the central weakness of their own campaign: an unpopular leader, championing redistributive policies that a number of voters evidently didn’t understand.

Even if the ALP was inclined to make vociferous complaints, it cannot be holier than thou about aggressively negative campaigns, having spearheaded the “Mediscare” offensive in 2016, which in some respects was a prototype for what played out in 2019. As one Labor insider puts it, the death tax scare of 2019 was a “get square for Mediscare – and then some”.

A death tax message spread on Facebook by One Nation on 22 April. Photograph: Facebook

“Mediscare” was political overstatement, but it was grounded in an actual proposal by the Coalition to examine outsourcing the payments system, which was given political potency by Tony Abbott’s deeply unpopular 2014 budget, which contained cuts to health funding and GP copayments. The then prime minister Malcolm Turnbull acknowledged this point when he talked after the election about Labor having “fertile ground in which that grotesque lie could be sown”.

The claims circulating from the beginning of 2019 that Labor proposed to introduce a death tax or a pensioner tax or a retirement tax were lies.

It was misinformation: fake news, open and shut.

But the “grotesque lie” (to borrow from Turnbull) was potent because Shorten proposed changes to franking credits that were construed by Labor’s political opponents as a “retirement tax”, a description widely used as shorthand in media coverage, a feedback loop that amplified the fake news. While it suffered as a consequence of misinformation, Labor did not have clean hands in this. At one point, it posted its own “death tax” content asking why Scott Morrison was refusing to rule such a policy out.

While the contest in 2016 was a harbinger, the federal election of 2019 will go down in history as Australia’s first post-truth campaign. Substantial numbers of people shared material on Facebook that had absolutely no basis in reality, and a lot of it was shared as personal communications between networks of friends, which means there is no requirement that the content be authorised in accordance with the electoral rules, even though it was clearly political communication.

The weaponising of misinformation through peer-to-peer sharing, and the lack of oversight or any meaningful intervention to stop it, suggests this is a significant weakness in Australia’s already lax electoral regime.

Political parties are vulnerable in an online environment akin to the wild west, and more importantly, citizens are vulnerable if they cannot sort fact from fiction.

Some Labor MPs still are not sure whether they lost support predominantly because of the contentious tax-and-spend policies Shorten advanced, or because of policies he never advanced – a deeply disconcerting experience and one with profound implications for democratic contests in the digital age.

Where did the death tax claims start?

The roots of the death tax falsehood go back almost a year.

An investigation by Guardian Australia spanning the election campaign and the aftermath suggests three key events laid the foundations for the scare campaign: a Daily Telegraph article on 21 July 2018 reporting that the Australian Council of Trade Unions supported an inheritance tax, an uncritical follow-up discussion on the Sunrise program the following day, and a media release by Josh Frydenberg on 24 January 2019 warning of Labor’s supposed plans.

Facebook Twitter Pinterest A Facebook post from George Christensen on 22 April. Photograph: Facebook

Frydenberg wanted to revive the offensive he had been running about Labor’s tax measures, which was largely dormant. There was no grand strategy to make the death tax a thing; the thinking was to keep Labor on the sticky paper about negative gearing and franking credits as the new political year, an election year, opened.

In the early stages, death tax content was shared on Facebook only sporadically, usually by fringe figures in a seemingly uncoordinated way, largely by a small cabal of politicians and groups in Queensland.

The Sunrise clip was shared by One Nation leader Pauline Hanson’s official Facebook account the same day it aired. Hanson’s post alone was viewed 106,000 times. LNP members Ian MacDonald and George Christensen began to push the death tax messaging from their Facebook pages in late January and early February, but their posts achieved relatively little engagement.

Facebook Twitter Pinterest The Sunrise clip shared by Pauline Hanson’s Facebook account.

At the same time as the misinformation was just beginning to take root, Facebook executives were on their way to Canberra.

Guardian Australia has learned the social media company offered Labor’s campaign strategists a briefing about how it intended to safeguard the integrity of the election. On 6 February, Facebook’s director of policy for Australia and New Zealand, Mia Garlick, arrived at ALP headquarters in Canberra, delivering a power point presentation called “Informed Community & Election Integrity”. She was joined in the room by Josh Machin, the company’s public policy manager. Among those listening was Labor’s national secretary, Noah Carroll, and the party’s digital team.

Garlick acknowledged there was interference in elections, and she said Facebook’s goal was to disrupt that activity. She outlined the steps Facebook was taking to remove fake accounts and stifle the spread of fake news. She boasted of Facebook’s third-party fact checkers and their ability to identify false claims and limit their spread, either by discouraging individual users from reposting, reducing their prominence in users’ newsfeeds, or directing users to more accurate, related posts.

But Labor did not emerge from the briefing with enormous confidence. Senior strategists departed with the impression Facebook was more worried about elections due in 2020 in America, Europe, Taiwan and Pakistan.

Surges of misinformation

By April, with the federal campaign in full swing. The trickle of death tax misinformation pinging through Facebook had become a flood.

In the week leading up to Easter Sunday, 21 April, Guardian Australia’s project to monitor hidden social media campaigning began to pick up a series of direct Facebook messages being forwarded, seemingly en masse, to the private inboxes of individual users. Most simply read: “Labor, the Greens and Unions have signed an agreement to introduce a 40% inheritance tax.” The messages all linked back to Frydenberg’s January press release.

A Facebook message spread by an anonymous third party in mid-April. Photograph: Supplied

The Labor campaign headquarters, by then ensconced in Parramatta, detected the same activity. By Good Friday, the campaign was concerned enough to write to Facebook alerting it to the upsurge and asking for intervention against the “orchestrated message forwarding campaign” about the death tax.

The campaign also deployed its own rapid response. There was concern that responding to the fake news would serve only to amplify it. Key people understood they were now in a classic Catch 22 situation. So strategists tried to put together measures they hoped would counter, without amplification.

Labor told its supporters, people it could easily target, that Shorten was not proposing a death tax. A mini website was created that emphatically rejected the claim. Voters searching online for death tax information were also targeted. Labor placed Google search ads with information about the rebuttal.

But the message was proliferating beyond the direct messaging. Public posts were being detected carrying similar death tax content, again linking back to Frydenberg’s release. The public posts were coming from fringe Facebook pages and personal accounts.

Labor informed Facebook, according to correspondence seen by Guardian Australia, that there were “multiple, various accounts posting statuses linking to a post on Liberal treasurer Josh Frydenberg’s website from January 2019 claiming the Australian Labor party will introduce a death tax”. The campaign expressed concern that the platform was being used “maliciously to circulate fake news during Australia’s federal election”.

The death tax messaging on social media was being amplified by minor parties, including Clive Palmer’s United Australia party, which was engaged in saturation advertising, by fringe right-wing groups, and by individual Coalition senators. The LNP backbencher George Christensen published three Facebook posts on the topic on one day, 22 April. Christensen’s first post was titled “Labor’s secret plans for a DEATH TAX”. A day later, Rite-On, a right-wing group with a significant online following, published a post headlined “DEATH TAX – INHERITANCE TAX – DEATH DUTY, call it what you will, it will hit us all”.

Other fringe groups such as “Snap Out of it Australia” and “I Stand by Tony Abbott” were also publishing death tax posts, as were popular alt-right groups reportedly linked to Fraser Anning, which shared memes picturing Shorten as the grim reaper.

On 23 April, the first paid ad linked directly to an official Liberal account appeared. Victorian senator Jane Hume’s page pushed the content into the feeds of targeted Facebook users, which compared Labor’s promises not to introduce a death tax to Julia Gillard’s promises that there would be no carbon tax – echoing the messaging in the pro-forma posts in circulation.

An ad spread on Facebook by Liberal senator Jane Hume. Photograph: Facebook

But then the activity seemed to calm for about a fortnight. Labor headquarters prepared for the official campaign launch in Brisbane, scheduled for 5 May. But the lull was just a blip. Strategists monitoring public platforms noticed a second significant upsurge in sharing activity in the days following the launch.

There was also a massive spike in Google search activity on Labor and death taxes, according to data being kept by the campaign, in the middle of that week. Search volumes increased roughly fourfold between 5 May and 7 May.

The Parramatta HQ saw a pro-forma post turning up all over Facebook which purported to explain how Labor’s death tax would work. The origins of the post were entirely unclear, but did not look amateurish. The post estimated the estate tax children would pay on assets bequeathed to them by their parents, and it also contained the comparison to Gillard’s broken promise on the carbon tax.

“Now, Labor have said they won’t be introducing a death tax,” the posts read. “Fair enough. The problem is though, Labor has form. Julia Gillard promised: “there’ll be no carbon tax under a government I lead!”, yet once elected, with the support of the crossbenchers....we had a carbon tax, until it was repealed by Tony Abbott.”

Labor seeks urgent intervention by Facebook

With the contest entering the closing stages, Labor again contacted Facebook to request urgent intervention. A fresh dossier of material was handed to the social media giant on the weekend of 11-12 May. There were high level contacts between Carroll and senior Facebook executives, but also staff-to-staff interactions. Facebook staff said they did not believe the sharing was the result of an organised campaign driven by bots that would indicate the possibility of foreign interference.

On 14 May, five days out from election day, Carroll and other Labor campaign staff had a second phone hook-up with Garlick and her team. Carroll later told colleagues he did not mince words, declaring the platform was disseminating flat-out lies, not the exaggerations of daily politics, and Facebook was accepting advertising money from politicians promoting lies.

The Labor operatives did not allege foreign interference, but compared the misinformation to episodes in the American presidential campaign of 2016, and during the Brexit referendum campaign in the UK. “We stressed from our perspective, this could not be any more serious,” one insider says.

Facebook responded by advising it had looked at the supplied material and referred it for third-party fact-checking. Some of the material had been found to be false and would be subject to demotion in the Newsfeed. Carroll sought clarification about what that meant. Facebook advised this meant the material would be less prominent.

Timeline Labor's contact with Facebook over fake news concerns Show Hide • Facebook first met Labor on 6 February 2019. Executives from the company gave senior Labor campaign strategists a briefing about how it intended to safeguard the integrity of the Australian electoral contest. Labor wasn’t convinced by what it heard. • With the election campaign under way in April, Labor approached Facebook over the Easter weekend in April to raise concerns about a spike in sharing of fake news about a death tax, fearing the activity was an organised campaign of misinformation. The Labor campaign also launched its own rapid response to counter the death tax claims. • As false claims continued to proliferate, Labor approached Facebook with a dossier of material on 11 and 12 May, and followed this up with a second conversation on 14 May, asking for action. It was unhappy with the response, and asked the company to escalate the inquiries and report back. • On 16 May, Labor’s national secretary, Noah Carroll, had a teleconference with Facebook’s Asia-Pacific vice-president, Simon Milner. He promised an urgent report on the scale of the sharing. But that report has not been forthcoming.

During this conversation, the Facebook executives said not all the material had failed fact checking, and in any case, fact checking applied only to general Facebook users, not to any content posted or promoted by politicians or parties. In any case, the social media giant did not want to play censor when it came to political claims.

Carroll was dissatisfied and said he wanted the matter escalated within the company. As the campaign entered the final week, some evidence emerged of a coordinated and well-financed effort to boost the messaging.

Liberal headquarters insists it played no role in the proliferating social sharing, and senior figures downplay the contribution of fake news to the election result, but the Morrison campaign was clearly happy to amplify the contentions. The Liberals paid for a series of ads running from multiple Facebook accounts from 13 May, all mirroring the death tax messaging.

A Facebook post outlining the supposed detail of Labor’s death tax. Photograph: Facebook

The ads featured a video titled “Why is Bill Shorten so defensive about an inheritance tax?”, which spliced together vision of multiple Labor candidates repeating the words “death tax” and “secret plan for a death tax”. This was the embodiment of Labor’s feared Catch 22: that they would stoke their own fake news problem.

Those ads, which Liberal insiders insist were a minuscule proportion of a campaign advertising buy doubtless running into millions of dollars, ran from the central Facebook accounts of the Liberal party and LNP, as well as from the pages of MPs Peter Dutton, Ross Vasta, Ken O’Dowd and Warren Entsch, among others.

To put the death tax intervention in context, in total the Liberal party posted about 200 videos from mid-April to campaign day on its Facebook page, and made more than 600 posts.

State-based MPs also began paying for Facebook ads to amplify the message. Colin Boyce, a Queensland state MP, used money from his own budget to boost an ad stating: “A Death Tax is a real possibility under a union controlled Labor Government. A families [sic] house in the city or a family’s rural property may have to be sold to pay a Labor Government 40% Death Tax.”

Asked how such a claim was justified, Boyce tells Guardian Australia he was simply relaying a screenshot of the almost year-old Daily Telegraph story about the ACTU. “I have used my own personal funds to boost the screenshot because people in my electorate couldn’t afford a Labor federal government,” he says.

A paid Facebook ad spread by the Liberal party on 13 May. Photograph: Facebook

On 16 May, in response to Carroll’s request for an escalation, Facebook put forward Simon Milner, the Singapore-based vice-president of the company in the Asia-Pacific. Milner reiterated the advice given by Garlick, but told Labor’s digital team he would provide a report with some urgency on the concrete steps Facebook was taking to limit the damage.

Election day came and went, and Labor is still waiting for that report.

This week, Carroll wrote to Milner reminding him that he had promised to supply a report demonstrating “identifiable and measurable steps Facebook had taken to combat the spread of this specific misinformation campaign”.

“I am yet to receive any information beyond a reference to a broad and generic second last week activity report which failed to list death tax as an issue being searched amongst several at all,” the national secretary said in his letter.

Carroll wondered if Milner would be so kind as to advise when the report might be received.

Facebook has taken huge and damaging hits for its performance in both Brexit and the 2016 US election. The social media giant now finds itself in a precarious position, balancing its clear duty to combat disinformation with its reluctance to become chief censor.

The company’s middle ground is to attempt to contain the spread of falsehoods through third-party fact checking. It’s an arrangement that led it to partner with the news agency Agence France-Presse.

Facebook’s fact-checkers review stories, detect mistruths, then take steps to limit their spread. They were quickly set to work on the death tax claim.

“AFP fact-checked this claim in April, and the post was rated as ‘False’,” a Facebook spokesman said. “Based on this rating, people who shared the post were notified that it had been fact-checked and rated as false. As a result, the original post and thousands of similar posts received reduced distribution in News Feed.”

Declaring a post “false” typically reduces its future views by an average of 80%. Users are also notified if they are about to share or have received a false post, while more accurate links are pushed to the user.

The fact-checking has its limits. Private posts and posts by political figures are not checked for accuracy. This allowed much of the death tax misinformation – paid ads by political figures, for example – to carry on unimpeded.

Misinformation prompts calls for truth in advertising

Cathy O’Toole lost the previously ultra-marginal seat of Herbert to the Liberals on 18 May. She believes her struggles during the campaign were largely due to Labor’s uncomfortable fence-sitting on the Adani coalmine. O’Toole insists perceptions that Labor was not interested in blue-collar jobs was the primary factor behind the loss.

But the death tax fake news didn’t help. In O’Toole’s part of the world it was called a pensioner tax, which was a misunderstanding about the franking credits policy. “These poor people were terribly distressed, really bamboozled and confused, and there were significant numbers of them in the last two weeks,” O’Toole says. Every night, several older voters were telling her phone-banking team that Labor would impose a pensioner tax, or something like that. “People thought they were going to be hit.”

It was the same in the Blue Mountains, west of Sydney. Susan Templeman, who is clinging on in the seat of Macquarie, says there was a broad retirement tax concept in circulation among her constituents. This was a combination of fake news and Labor’s inability to explain its policies. “We have to be responsible,” she says. “We used language that didn’t spell things out clearly enough. Had we done that better, we might have been able to quash some of these fictitious claims.”

Separate to the tax issue were materials circulated by a group called Cherish Life claiming Labor supported late-term abortions. Flyers were tacked up outside pre-poll booths. There was letter-boxing in the electorate. “I was still phoning people on the night before the election trying to rebut this,” Templeman says. “It was disgusting. That was one of the most horrific campaigns that I’ve seen that had no factual basis.”

After the 2019 campaign, which felt like a long walk in a hall of mirrors, Templeman is in no doubt about what needs to happen. “We really need truth in political advertising,” she says.

“When people see material is authorised by the Australian Electoral Commission they make assumptions it’s true, but the AEC has no responsibility to check whether any authorised claim is true. We need to make this regime consistent with what people expect as consumers.”