Labor leader Bill Shorten has had to clarify comments on the possible location of a future offshore detention centre after suggesting to The Saturday Paper it could be in “western Papua”.

In a wide-ranging interview this week, the man vying to be Australia’s next prime minister confirmed a Labor government would not end offshore detention of asylum seekers and refugees and would consider shifting the Manus Island centre if Papua New Guinea wanted it moved.

He nominated “western Papua”, in what initially appeared to be a reference to the hotly disputed region of Indonesian West Papua.

“If Manus doesn’t want it and they want to have it in western Papua, I’m not going to argue with PNG,” Shorten said. “But will I have regional processing? Yes.”

After The Saturday Paper queried whether the Labor leader meant Indonesia or Papua New Guinea, a spokesman sought to clarify the remarks. He said Shorten had been referring to a western province of Papua New Guinea and not West Papua. This is the first time Shorten has suggested he might contemplate moving the detention centre elsewhere, even in PNG.

Shorten’s verbal shorthand came as he emphasised the importance of Australia being well versed on its own neighbourhood.

Asked what kind of country he wanted Australia to be under his leadership, he nominated as a priority being properly engaged in the Asia-Pacific region.

“From this side of the dateline to somewhere in the Indian Ocean south of the equator, we should be topic matter experts on our region,” Shorten said.

The previous night, during a solo performance on the ABC’s Q&A that suggested a leader growing in confidence, he also spoke of the need to pay more attention to the region and vowed that Australia’s international relationships would be a Labor government’s first-order issue. “It’ll prioritise working in the Pacific, with New Zealand, with Indonesia, with our near neighbours,” he said.

The Saturday Paper spoke with Shorten midair on Tuesday afternoon, as the Labor leader flew back to Canberra having followed Sunday’s Labor campaign launch in Brisbane with a swing through Western Sydney and regional Victoria.

Shorten believes he is as ready as anyone can be for the nation’s highest elected office, having spent six years in the role he says offers the best training. “You’re tested, you’re scrutinised, you learn, it gives you thinking time.”

Shorten defended his decision to persist with detaining asylum seekers offshore, despite pressure to abandon the policy from both refugee advocate groups and members of his own party.

“I don’t want the people smugglers to sell a model that if you come to Australia you can stay,” Shorten said, rejecting the argument that turning back boats was the greater deterrent.

“I think it’s more than that,” he said. “We will do regional processing. Whether or not it’s those facilities or… [elsewhere].”

When asked where an alternative centre would be located, if not on Manus Island, Shorten offered the “western Papua” suggestion. “We’ll do what it takes,” he said.

It is not the first time Bill Shorten has had to clarify something said during the campaign.

The Liberals seized on his response to a well-paid shiftworker at Queensland’s Gladstone Ports two weeks ago, who asked if Shorten would cut tax for those on incomes above $250,000.

“We’re going to look at it,” Shorten said, later conceding that in fact Labor planned to increase tax at the top end by 2 percentage points.

A week earlier, he was also forced to declare a mistake after telling journalists he had no plans to change superannuation tax concessions.

Labor announced three years ago that it planned to cut tax concessions on super contributions if it won office. Shorten insisted later that he thought he was being asked about further concessions.

While loose language is dangerous during an election campaign, Shorten has been more willing to expose himself to lengthier interrogation than his opponent, Prime Minister Scott Morrison, whose campaign has featured set-piece events, occasional casual street walks – something Shorten has largely avoided – and news conferences with travelling media.

Despite the stumbles, Labor has maintained its lead in the published polls.

The Saturday Paper questioned Shorten across a range of policy areas.

He spoke about his hopes for Australia and his plans for the economy, not ruling out brokering a new Accord-style productivity, wages and training agreement between business and the unions, similar to that of the Hawke era.

“I’m thinking about how we can work more closely together,” he said. “I’m not worried about the nomenclature.”

Shorten flew out of Avalon Airport, near Geelong, on Tuesday, headed for Canberra and a planned side trip to the marginal coastal New South Wales seat of Gilmore ahead of Wednesday night’s final leaders’ debate at the National Press Club. He had come from a visit to the high-tech Carbon Revolution factory near Geelong, a successful local business in the very marginal seat of Corangamite.

As he hoisted an 8.5-kilogram carbon-fibre wheel rim and was told it was 40 per cent lighter than the aluminium alternative, two watching workers offered some free advice.

“One hand!” they said, grinning. “Malcolm Turnbull did it with one hand.”

The business is an established campaign stop and the workers were making it clear they had heard election pitches before. This time, though, Turnbull is a far-off past leader and Shorten faces both a new opponent and the prospect that in a week’s time, as the polls suggest, he is on course to become Australia’s prime minister.

Shorten’s response to the big-picture question began with the thesis that Australia had to “start thinking big”.

“We want to be a country that thinks big, that writes Australia big,” he said. “We’ve been told for a long time that every problem’s too hard, that if you want to reform, if anyone’s unhappy you can’t do it. [That] the politics of hope are always going to lose to the politics of fear.”

The politics of hope generally flourish more readily when their advocate is charismatic and popular. Barack Obama’s 2008 campaign in the United States is the oft-cited example.

Bill Shorten makes no particular claim to such charisma and the opinion polls suggest he’s not personally popular. But he is pushing on with hope, regardless.

Asked how he would rebuild the damaged trust between Australian voters and politicians after a decade of revolving-door leadership changes in which he played a role, he said: “We trust the Australian people with our policies. If I want them to trust us, I have to demonstrate I trust them.”

He has shunned the common small-target strategy of oppositions past and instead presented policy detail, despite the risk of alienating particular groups.

Shorten is vowing to focus tax cuts on low and middle incomes and to strip back concessions that have favoured the wealthy, real-estate investors and some self-funded retirees.

“If you get an income tax refund and you haven’t paid income tax in that year, it is not a refund, it’s a gift,” Shorten said of his contentious plan to end franking credits for non-tax-paying retiree shareholders, during Wednesday’s leaders’ debate. “Now, it’s not illegal, it’s not immoral – it’s the law. But it’s not sustainable.”

Morrison attacked Shorten’s credentials, saying Labor would bring “$287 billion in higher tax and that will put a dead weight on all Australians, on small and family businesses which will hold them back at a time when we want them to be absolutely as match fit as possible”.

On one of Australia’s thorniest foreign policy challenges, Shorten told The Saturday Paper he did not view China “purely through the prism of strategic threat”.

“I don’t operate on a worst-case scenario as the only scenario,” Shorten said. “And when I … disagree or agree with the Chinese government on a particular issue, they will probably hear it from me first, rather than through some public humiliation.”

He did not rule out amending the controversial encryption laws about which he remains concerned and which led to a rare major-party split on national security.

“My style is much more consultative and I accept, listening and talking to experts in the IT industry, that a lot of this legislation is very clumsy and can have unintended consequences,” he said.

Shorten refused to name a possible Home Affairs minister before the election and confirmed Labor’s factions will retain their influence over his line-up.

Seemingly adjusting his words mid-sentence, he said: “I will let my caucus … work with me to pick the ministry.”

Traditionally, Labor’s factions choose ministerial candidates, with the leader assigning portfolios. Shorten will adhere to this process, which Kevin Rudd overrode during his prime ministership.

With the legislated maximum number limited to 30, and Shorten’s frontbench at 42, some cutting will be required. Shorten had personally elevated some himself to form part of a praetorian guard against leadership threats, after left faction divisions saw them omitted. While the divisions remain, Shorten effectively implied he would not do so again.

“I’ve shown my ability to work through issues in my party,” Shorten said.

He refused to quantify the cost of his policy to reduce greenhouse gas emissions by 45 per cent on 2005 levels by 2030, saying only that the “cost to government” would be $556 million. (This newspaper went to press before Labor’s full costings were made available.)

The Labor leader insisted the questions about cost were wrong because acting on climate change was not optional.

“Scott Morrison is looking through the exhaust pipe of history on climate change,” he said. “Why don’t we look at the cost of inaction?”

Shorten reached for a metaphor, first trying one about the transition from horse and buggy to car, then mobile phone technology, not disposing of chemicals in rivers and throwing burger wrappers from car windows versus pulling over and putting them in the bin.

He settled on an asbestos analogy.

“What is the cost of us not using asbestos in our buildings? You know what a fundamentally stupid question it is.”

He used it again in the debate the following night.

On the Adani corporation’s proposed coalmine, Shorten insisted he had given no undertaking to the Construction, Forestry, Maritime, Mining and Energy Union to allow it to proceed, only that science and sovereign risk would dictate any decision. He neither confirmed nor denied that his recent rhetoric had hardened in favour of allowing the mine.

Asked if he was prepared to stimulate a slowing economy, as the Rudd government did during the global financial crisis with its controversial programs for school infrastructure and home insulation, Shorten said: “I’m going to create a surplus which is a national fighting fund … The sweet spot is productivity. Monetary policy is not the silver bullet anymore.”

Core to Shorten’s campaign is “fairness”, particularly a push for higher wages. He has said a Labor government would intervene to boost the wages of low-paid early childhood workers. On Monday night, he suggested he might look in future at aged-care workers too.

In the Tuesday interview, he seemed to retreat back to childcare. “I think the solution we’ve come up with there is fairly unique for that sector,” he told The Saturday Paper.

Shorten believes he is as ready as anyone can be for the nation’s highest elected office, having spent six years in the role he says offers the best training. “You’re tested, you’re scrutinised, you learn, it gives you thinking time,” he said. “In the modern digital era, with media concentration, it is not for the fainthearted. But I never thought I’d say this – I wouldn’t swap a day of it.”

To that declaration, he added what would become a prescient, personal caveat. “Except other than perhaps the day Mum passed away,” he said of his mother Ann’s death five years ago.

Shorten was extremely close to his mother, who largely raised him and his brother, Robert, as a single parent after she divorced, and he is known to be particularly protective of her memory.

So when Sydney’s The Daily Telegraph published a story accusing him of airbrushing out part of her employment history in a brief anecdote on Q&A about cost pressures having forced her to opt initially for a teaching scholarship over studying law, he saw it as a deliberate, partisan attack.

The newspaper suggested it was dishonest not to explain that Ann eventually studied law in her 50s and won the Victorian Supreme Court prize.

Shorten’s response to the newspaper and its headline – “Mother of invention” – became a galvanising moment in the campaign. If the paper’s treatment was designed to knock him sideways, it had precisely the opposite effect.

The man who the polls suggest has struggled to connect at a human level gave a deeply personal and passionate defence of his mum and of all women who try to realise career dreams at mature age.

Having completed her degree, Shorten explained, his mother had found the system stacked against women of her age, receiving just nine legal briefs in what was a short practising career.

As Scott Morrison also does, Shorten can sometimes bristle with suspicion and a readiness to fire that may just be a byproduct of public life in the unforgiving social media age. But this was a different man, fully open and devastatingly present. Fighting tears, Shorten said his mother was “brilliant”.

“Just because you’ve got grey hair, just because you didn’t go to a special private school, just because you don’t go to the right clubs, just because you’re not part of some backslapping boys’ club doesn’t mean you should give up,” he said in a comprehensive return of fire to what he called a “rubbish” story and “gotcha shit” about his life.

“My mum is the smartest woman I’ve ever known. It has never occurred to me that women are not the equal of men. It’s never occurred to me that women shouldn’t be able to do everything. That is why I work with strong women. That is why I believe in the equal treatment of women.”

The issue dominated a precious day’s news coverage and left Morrison in the position of having to back Shorten and criticise the newspaper’s “very upsetting” coverage.

Should Bill Shorten find himself in government after May 18, his to-do list is long and ambitious. “Why can’t we treat women equally?” he asked, rhetorically, during our interview. “Why can’t we have a manufacturing sector? Why can’t we have the best healthcare system in the world? Why can’t we have universal preschool for three-year-olds? Why can’t we have dental care for pensioners? Why can’t we have a strong minimum wage?”

Shorten embraces idealism. An Australian head of state. “True equality” between the first Australians and the rest. Foreign policy “with an Australian accent”.

He accused the Liberal–National incumbents of presiding over an economy “wallowing in mediocrity” and “in the freezer”.

“Nothing’s happening, nothing’s growing,” he said, before checking himself slightly. “That’s not quite fair, you’ve got good businesses, you’ve got some sectors doing well. Zero per cent inflation? God, that’s not healthy.”

In the days since Labor’s launch on Sunday, Shorten has begun to look more certain. He believes he’s done the work.

“It doesn’t mean that people will vote for me but it means that if they do, I genuinely believe I’m about as well prepared for this job as someone since probably the time of Whitlam,” he said. “And I don’t compare myself to Gough. But he was opposition leader for a long time.”

Shorten is not Kevin Rudd either, who successfully ended the Howard era by presenting himself as Liberal-lite.

Shorten wants to differentiate. He wants Australia to think “more boldly”.

Although he confesses to borrowing at least one of Malcolm Turnbull’s policies – on climate change – Shorten seeks to contrast a steady, six-year apprenticeship with the turmoil of removal and replacement.

With a week to go, his ongoing challenge is to both demonstrate and make a virtue of having both hands on the wheel.