John Healey is one of Labour’s great survivors. The Yorkshireman served in government for nine years and has been an MP for nearly 20. After leaving the shadow cabinet in 2011, he returned last year under Jeremy Corbyn, taking on the brief he once held in office: housing.

Few MPs have better knowledge of the sector than Healey but it was politics, rather than policy, that he was most keen to discuss when we met in his Commons office. “The central question for me, and it must become the central question for the party at every level, is ‘do we want to win the election?’” he told me. “It flows from what I’ve always argued, which is that the biggest political event for Labour last year was not Jeremy Corbyn winning the leadership election, it was the party losing the general election - dreadfully.”

Though he acknowledged Corbyn’s admission at a recent Parliamentary Labour Party (PLP) meeting that “we are not yet doing enough to win”, he warned that this “understates the scale of the challenge”. “If you take the national share of the vote, we gained 3.7 per cent. That leaves us a long way short of being able to put ourselves in a position to win in 2020. With no recovery in Scotland, we need a swing of over 10 per cent from the Tories to us. With that share of the vote across the country, we’d win 22 seats in England and three in Wales. Now, actually, we’ve got to win 100 across England and Wales ... It’s the seats we won in 1997, in many cases held in 2001 - and that’s before you get into the boundary changes.”

Healey was eager to dispel the myth that Labour can win through an electoral coalition of left-wingers, Greens, Liberal Democrats and non-voters. “If we want to win in 2020, or put ourselves in a place to win, then we’ve got to win Tory voters in Tory seats - that is the single big political challenge that faces us. It isn’t mopping up the non-voters, it isn’t mopping up the splintered Liberal Democrat or Green or left vote. The one thing we have to do, beyond turning our fire on the Tories and acting as a decent official opposition, is to turn our attention to Tory voters in Tory seats.”

The Wentworth and Dearne MP has long argued that Labour should focus on “Britain’s middle third: the real squeezed middle”. “The six million households or the 17 million people who are largely working hard on low incomes, who are in that third of the population on either side of the median income ... They’re essentially often too poor to get the best out of the market and too rich to receive much if anything in state benefits.”

Healey is a popular and respected figure in the PLP (he finished second in the final shadow cabinet elections in 2010) and urged his colleagues to unite behind Corbyn as long as he remains leader.

“You have a large swathe of the centre and the centre-left in the PLP that respects the leadership election result, that understands we have Jeremy Corbyn until we don’t have Jeremy Corbyn as leader, and that recognises that division distracts from our principal task of being a good opposition and holding the Tories to account and opposing the worst of what they’re trying to do”.

He added: “I’m serving in the shadow cabinet, that’s a signal and I explained my reasons for doing that on the very day he [Corbyn] gave me the job and that is: we have to make Labour as good as it can be and to take the lessons from that election defeat.

“That’s where our attention needs to be, not simply dealing with the question of whether we think Jeremy Corbyn is doing a good job as leader. We can’t win an election with anyone as a leader unless we tackle the fundamental challenges I’ve talked about.”

Would Healey like those former frontbenchers who refused to serve under Corbyn to return? “I want to see the best people in the shadow cabinet, that’s pure and simple, you make your judgement about whether some of the people outside the shadow cabinet are talents that we can’t afford not to use. If you look across the whole range of the Parliamentary Labour Party there are people outside who have a big role to play.

“As long as it’s directed to the things that matter most, I don’t care where in the party they stand politically, if their single concern is, like mine, to win the next election then I want to work with them.”

Healey told me that he had “no idea” whether Corbyn would remain leader until the next general election. “Let’s deal with what we face now and let’s make sure that we see clearly what we have to face over the next two, three, four years. The dreadful result leads to much deeper questions and a need for a much deeper rethinking. Our 1990s political revival was based on an intellectual revival, which is what I want to see.”

Before developing detailed policies, Healey said that his task as shadow housing minister was to overcome a “pessimism that things can’t change”. “Underlying my challenge is something that’s stuck in my mind from a big MORI survey that was published just before the last general election. 72 per cent of people said it would make little or no difference which party won the election to the housing problems in their area. Now, we had some good policies but actually they never added up to more than the sum of their parts and that was true in housing and it was true across the board. If we can’t come up with a vision of how things could be different for people - their families, their neighbourhoods, their towns and the country - and we can’t generate a conviction that Labour would make a difference and is capable of making a difference then Labour’s not even at the races.”

Healey, a long-standing champion of public investment, pointed to his proposal of 100,000 new council and housing association homes a year (“they would pay for themselves in 26 years and turn a profit for the taxpayer after that”) and an independent review into the decline in home ownership. “There’s a third of a million fewer homeowners under 35 than there were in 2010 when Cameron became prime minister.”

He derided “six years of failure” by the Conservatives “on all fronts”. “Homelessness is soaring, private rents are soaring, the housing benefit bill is ballooning. In the last parliament they built fewer new homes than any peacetime government since the 1920s. The level of new affordable homes is at the lowest level for more than two decades.”

One of the political challenges facing Labour is the forthcoming vote on Trident renewal - an issue that divides Corbyn from most of his shadow cabinet and MPs. Healey told me that he “absolutely” supported the maintenance of the present system. “Our Labour Party policy is very clear: we support an independent at-sea nuclear deterrent. It’s part of our power and place in the world to exercise influence and it’s part of the way that we are a bigger force in the world than we would otherwise be. The challenge is making sure we’re a force for good.”

He suggested that Corbyn should give Labour MPs a free vote on the issue. “Should there be a free vote? Given that the vote is not required for the continued investment in Trident, given that the vote is quite nakedly a political device by Cameron to try and divide us and put us on the spot, and given that the vote actually will mean little, I think if a free vote helps spike Cameron’s guns then a free vote is a good idea and we’ll make that decision in the shadow cabinet when we get close to it and we see the terms of it.”

Faced with the obstacles to regaining power, some in Labour argue the party’s future lies in “progressive” alliances with the Lib Dems, the Greens and even the SNP. John McDonnell, the shadow chancellor, recently called for Corbyn to back proportional representation. But Healey, a proud supporter of first-past-the-post, denounced this as a “distraction”.

“We have to win middle ground, centre ground England, Wales and Scotland to win the UK government back - that’s our challenge. Anything like that is a distraction and it’s waving a white flag.

“And I say this to party members and colleagues in the PLP, write off the 2020 election and it becomes a self-fulfilling prophecy. The one thing that we can be certain of in politics is change. We know Cameron has always been ahead of his party but he won’t be leading his party into the next election, we’ve got a Chancellor who’s not as clever as he thinks, an economy that is not as strong as we were told last year, Cameron has a majority of 12, Major had a majority twice that in 1992.”

For Healey, it is the increasing weakness of the government that necessitates a stronger opposition - but he lamented that Labour was falling far short.

“For the first time, people are starting to see a government, which is divided ... it’s directionless, it’s deeply unjuss. It’s leading people for the first time to question Cameron, Osborne, these Tories are competent are fit are right to be leading the country. That’s our opportunity but it’s also our challenge. It’s our opportunity because we can drive home our opposition and the reasons why people are right to ask those questions. It’s our challenge because if people are starting to ask those questions of the Tories for the first time, they will start to ask those questions of Labour as an alternative and we’re a long way off being capable and ready to answer those questions.”