Andy Burnham is just squaring up. The culture secretary is somewhat underwhelmed by David Davis’ decision to resign and fight a byelection as part of his self-proclaimed struggle with the surveillance state. ‘I think it’s a bad thing’, he begins. ‘Byelections should be called for real reasons, such as a death or an incapacity to do the job or serious fraud or wrongdoing,’ not because someone wants to ‘posture on a stage for a few weeks’.

Actually, continues Burnham, ‘the more I think about this thing, the more it staggers me as an outrageous act of arrogance.’ The former shadow home secretary, he believes, seems to have got this ‘idea that you can just go and flounce around for a few weeks and go around the TV studios because you fancy it’. It’s clear that ‘Basher’ – as the former amateur boxer, SAS man and two-times Tory leadership candidate is affectionately known in his Westminster stomping ground – holds no fear for the culture secretary. ‘I actually feel it’s fairly insulting to his electorate because it’s basically saying: “I’m going to use 70,000 people in my national stunt.” They’re not there to be used in that way.’

Perhaps Burnham thinks the former Tory frontbencher should pay the cost of the byelection? ‘Yes, I do. I think there’s a bloody good case to be made for it. Why should the resources at local level and national level be devoted to this? Why? We don’t need to be told about them again for three weeks, just write a few more newspaper articles.’

But in the culture secretary’s book, there seems to be only one thing worse than Davis’ ‘posturing’ and ‘flouncing’ and that’s those who have fallen for it: ‘To people who get seduced by Tory talk of how liberal they are, I find something very curious in the man who was, and still is I believe, an exponent of capital punishment having late-night, hand-wringing, heart-melting phone calls with Shami Chakrabarti.’

After months in which Labour has seemed to be rolling with the punches, it comes as a surprise to hear a cabinet minister so assuredly on the attack. But Burnham’s confidence seems to stem, in part, from a certainty that, on the issues on which Davis has chosen to take a stand, Labour is in tune with the voters. ‘Much is made of the intrusive state, the top-down state, I don’t think we’re on the wrong side of this with the public – I think we’re very firmly on the right side,’ says the culture secretary.

‘When Labour councils have tested these issues locally they’ve always been pushed by the public to go further, not to be meek and timid in the face of problems to do with antisocial behaviour and violent crime,’ he continues. ‘I think we are basically in the right place: that’s not a recipe to be more macho and aggressive, but it is to make a considered defence of the proposals that we put in place around issues such as the DNA database, the proposals we’ve got around national security and terrorism. We mustn’t be defensive about making these arguments because the public support us.’

The government didn’t seem, however, to gain much politically from its decision to fight for 42 days detention of terrorist suspects, a measure which, according to the polls, two out of three voters supported. ‘For me it’s not about reaping a political dividend,’ argues Burnham, ‘but it would be political weakness to say we can’t take a decision on that anymore because we’re not sure whether we can win it in parliament. I think it’s a sign of political strength basically that we were able to, and did, make the argument in the Commons.’ And the culture secretary is unwilling to accept some of the liberal characterisations of Labour’s record: ‘I think there’s something of a myth that’s grown up around how cavalier the government is with liberties. Supposedly, we just enjoy trampling all over them and being gratuitously top-down authoritarian. That’s not the case at all.’

Nonetheless, Labour will enter the next election in somewhat unchartered political waters. At the last two elections, the party managed to frame the choice before the public as ‘Tory cuts’ versus ‘more schools and hospitals’. Does Burnham fear the consequences of Cameron’s attempts – most notably through the pledges to match Labour’s spending plans – to erase this divide? ‘One of the amazing things for me about politics today is the extent to which to the Tories have bought our basic analysis and remedy for Britain … I don’t see them anywhere challenging those basic notions around levels of public spending.’ He argues that Cameron’s abandonment of proposals he was pushing as recently as 2005, like the patient’s passport, suggests the old Tory ideology is now ‘fundamentally holed below the waterline’.

But if Labour has, as the culture secretary claims, ‘won the argument’, why does it seems as if it’s the government, and not its opponents, which is now sinking? Burnham accepts that last autumn’s ‘election that never was’ marked a turning point: ‘Momentum’s a curious thing in politics: how you get it when you’ve not got it and how you lose it when you have it. Thousands of us who’ve worked around these jobs could sit in a room and try and work out how to get momentum and how not to lose momentum, but the truth is it hinges on the most unexpected little moments in politics and clearly that has been a key point where we did lose momentum.’

For some, of course, the party’s difficulties represent more than simply a loss of momentum. Do not the plunging opinion polls, Tory victories in the London mayoral and local elections, and the disastrous loss of the Crewe byelection suggest something rather more profound: the ‘death of New Labour’, perhaps? ‘It’s convenient for some to claim it, but I would say that is absolutely far from the case,’ the culture secretary responds.

For Burnham, though, the political is somewhat personal. Like current cabinet colleagues David Miliband, James Purnell, Ed Miliband and Ed Balls, most of Burnham’s working life has been closely tied to the party. Like them, he spent Labour’s last years in opposition working in parliament and served as a special adviser in the heady days after Labour’s victory in 1997 before entering parliament and rising through the ministerial ranks after the party was returned to office for a second and third time. ‘You’ve got a generation of young people who are 45 and under who came through the same experiences and, incredibly, are still very much together despite what we’ve been through. You saw how Labour governments of the past became completely riven; we don’t have that,’ suggests the culture secretary.

‘In some senses,’ he continues, ‘I felt a mistake we made at the very beginning was [not] to say that this is a 20-year job. We should have talked about the New Labour project in those terms.’ So why didn’t they? ‘Because we were young people in a hurry and thought it was all going to get better overnight, that things can only get better, [and] that on day one it would all miraculously start looking marvellous, and that was naïve really.’

Burnham admits this youthful impatience bears some responsibility for the party’s current travails and the ‘impatience’ he detects in the public: ‘We should have been perhaps much more honest about how long it would take to turn round the NHS [and] schools, to a point where the public could really see that these services were different. If we had conditioned expectations a bit more in that way, perhaps there would be a clearer sense of the longer-term journey.’ Things will start getting better? It doesn’t have quite the same ring.