"My children have been on to me about getting a guinea pig," she laughs. "What's a rat? It's a guinea pig with a tail." Frustration is mounting about the slowing of internet speeds, says deputy opposition leader Tanya Plibersek. Credit:Wolter Peeters As Labor's deputy leader and one of its best performers (betting houses now rate her as the favourite to take over from Shorten should he lose the election campaign), Plibersek has relegated her usual preoccupation with foreign affairs for a gruelling circuit of appearances through marginal seats. Plibersek sits in on major campaign tactics meetings and is expected to speak widely on issues. She also faces a challenge in her own seat from the resurgent Greens, even if Labor strategists remain confident she will win, more so than in neighbouring Grayndler where Anthony Albanese (another Labor leader-in-waiting) is facing a bigger challenge. She's keen to talk about what she reckons could be the sleeper issue of the election campaign, certainly one that she says is gaining traction in her own seat.

Frustration, she says, is mounting about the slowing of internet speeds as the telecommunications network gets overloaded as households' consumption of data rises dramatically. Dubbed the "Netflix effect", the amount of data sucked through the copper-based cable network, much of it driven by streaming services such as Netflix and Stan, has doubled in the past year or so, and continues to rise at record rates. Tanya Plibersek with Labor leader Bill Shorten - and the rat left at their feet while campaigning. Credit:Alex Ellinghausen "It's huge, it's a very big issue in my electorate," she says. "There is the typical domestic user who is irritated but I've also got the creative start-up businesses, people who work from home ... They rely on a really good internet connection to be able to do business with the world. The operate globally and they need to send very big files." With the National Broadband Network – Australia's biggest infrastructure project – facing delays and cost blowouts and inextricably linked to Prime Minister Malcolm Turnbull due to his previous role as communications minister, it provides Labor with what Plibersek describes as a "potent" line of political attack. Tanya Plibersek's son Louis with the rat he and his siblings named Harry.

"It elicits an angry response about Malcolm Turnbull. He's telling everyone he understands about innovation and he understands what it takes to run a startup and build it into a big business," she says. "The personal experience [of start-ups and households] is they are dealing with all these frustrations because their internet is pathetic." While the NBN flared in the election campaign as an issue when the Australian Federal Police last month raided the office and homes of Labor staffers searching for leaked documents from NBN Co, Plibersek believes the problems with internet access and speeds will linger throughout the campaign. Only 2 million of 12 million homes have been connected to the NBN. The longer it's delayed, the worse the problem with internet speeds will get, says Mark Gregory from RMIT University's school of engineering. "You have all these providers that re-sell ADSL [the most popular form of delivering the internet for those without the NBN]. They are doing the bare minimum to upgrade the network because they know they are going to be eventually replaced by the NBN." The government maintains that its model for the NBN, which relies more heavily on delivering the NBN to "nodes" rather than taking the high-tech cable direct to homes, is cheaper and faster to rollout than Labor's "gold-plated" model, saving taxpayers $30 billion.

Along with the NBN, Plibersek cites the economy, health and education as the biggest issues of the campaign, revealing that candidates have a run-down on how much each school in their electorate will gain under Labor's policy of boosting funding in line with the recommendations of the Gonski report. It's the type of grass roots politicking that worked well with Queensland and Victorian state campaigns, where Labor surprised by upending first-term governments. Labor needs to pick up – as well as hold – a swath of seats in western Sydney if it has any chance of replicating those victories at the federal level. The $17 billion Westconnex motorway being built by the NSW government runs through many of those seats. It's a tricky political issue for Labor. Its western Sydney MPs are strongly in favour of the project, which aims to cut commuting times into the city dramatically. But the new network of roads and tunnels will disgorge many motorists in Plibersek's electorate, potentially creating gridlock. It is deeply unpopular among many inner-city dwellers. Plibersek attempts to walk the line between unsparing criticism of the project while not deviating from the party's position. "This is a road planning disaster on a grand scale. You are just moving the traffic jam closer to the city," she says. "Helping with western Sydney traffic congestion, that's something I can totally get on board for. Doing it with this ridiculously poor planning and very little community consultation, well, that I'm less enthusiastic about it." If it wins government, Labor won't – indeed, can't – withdraw funding, she says.

"Bill and Anthony and I agree 100 per cent on this. We have all been critical of the process and the lack of transparency around the project. It is a monument to Tony Abbott's obsession with rolling out road projects as quickly and sloppily as he possibly could." Plibersek is noncommittal about what Labor, if it won federal government, would do about Westconnex. Any plan to extend the motorway to Sydney airport (and the port at Botany Bay), thereby bypassing the inner-city traffic jam, would likely cost extra billions of dollars. For Plibersek, her own electoral fortunes rely heavily on whether the Greens candidate Sylvie Ellsmore can outpoll the Liberal candidate Geoffrey Winters. Plibersek looks to have a win in the bag, if perhaps suffering a cut to her margin of victory. Even so, she says: "I'm never confident. I'm a real worrier." Follow us on Twitter