By Tom Happold and Conor Pope

Andy Burnham is surprisingly chipper for someone who has slipped from frontrunner to second place in the Labour leadership race. “I believe I can still win this race. If you look at the numbers, I’m increasingly the only one who can win this race other than Jeremy.” So certain is he, that he is not planning to use his second preference.

We spoke to Burnham as his team was sending out an eight-page manifesto to the 600,000-plus people who are now entitled to vote in the leadership election. He is unfazed by this influx. “When these new rules came in the idea was to open up politics and I think we can say it has succeeded … Don’t be frightened of the debate now it’s broken out.”

But he is frustrated that more of Labour’s selectorate do not see him as someone who shares their hunger for change. “I’ve lived at the top of politics for quite a while and I’ve found myself become disillusioned with its style and lack of substance. I want to change it from within. But it doesn’t give you the feel of the insurgent, does it?”

Burnham sees the welfare vote as a “watershed” moment in the leadership contest. He opposed the bill but obeyed the whip and abstained. Jeremy Corbyn voted against. “Three of us were members of the shadow cabinet, and one of us wasn’t,” he explains. “I’m not someone who’s ever gone in for grandstanding and big gestures, or putting myself over the interests of the party. I didn’t over that and I wouldn’t going forward.”

Asked if he has ever broken the whip, he shoots back a straight one-word answer: “No.” Is that important? An emphatic yes.

“There are two schools of thought: some see politics as an individual sport, others see it as a team sport. I see it as a team sport. The more united you are, the better you are able to do what you’re trying to do.” Burnham does not attack serial rebel Corbyn directly in our interview, but his criticism is implicit.

There are also two schools of thought about Burnham. The first is that he is someone who has trimmed to the left since Labour left office – in the hope of appealing to party activists – and has helped create the conditions for the Corbyn insurgency in the process. The second that he is a genuine Labour loyalist, who could appeal to those alienated from the party over welfare, immigration and the deficit while staying true to the party’s values.

Burnham’s conviction as to why Labour should oppose the welfare bill suggests he is no opportunist. He thinks the party should focus on the substance of the bill not the Tories’ messaging about it. “How could the Labour Party sit on its hands when all the things we did around tax credits are being unraveled? Are we so lacking in self confidence now that we can’t defend one of the big achievements of our government?”

“I’d love to see the piece of evidence that says the public don’t support supporting people in work, because I think most of them would do. I’ve not seen any evidence that people want to see a diminishing of our commitment to tackling child poverty.”

But Burnham does not believe in no compromise with the electorate. “People want a sense of fairness. They want the rules to mean something; that the system shouldn’t be there for people who are trying to avoid working. People want to see those rules enforced. They don’t want to see people able to access the benefits system the minute they arrive in the country.”

“You’ve got to find a point of balance in this debate, where you face up to the concerns people have, but you develop Labour answers rather than swallow what the Tories say.”

The idea of balance goes to the heart of Burnham’s appeal. He believes the party, and its newly expanded membership, want a different style of politics but one that can also win. He thinks he can return to more traditional Labour values and reach out to those who rejected the party. He regards his manifesto as radical, credible and deliverable. We will know soon if enough people agree with him.