DAN HODGES: An hour after Burnham's social care pledge, a text arrives from one of his allies. 'I think there will be an election in May.'

To be fair to Andy Burnham, no one can say they don't know what he stands for anymore.

Appearing on the BBC's Laura Kuenssberg show, the Prime Minister made the boldest commitment of his premiership by announcing the establishment of a National Care Service, free at the point of use, paid for by everyone.

Speaking passionately, and at times even emotionally, Burnham declared: 'Some in the political world will be saying watching this, Oh my goodness, what a hostage to fortune, that's a rod for his own back. But do you know what, I am not going to do politics as usual.'

Watching the broadcast, in which he talked eloquently about the national scandal of inadequate provision for our most vulnerable citizens, it was easy to see why Labour's new leader is enjoying a polling bounce. Whatever your views of him and his government, he speaks human. Which represents a refreshing and notable change from his immediate predecessors.

But he is also right. He has indeed saddled himself and his party – and potentially the entire country – with an enormous hostage to fortune. One that could literally cost every one of us dear.

First there is the policy itself. Burnham is right when he says the current care system is in crisis. But the sheer scale of that crisis simply reinforces just how much hardship could be placed on the shoulders of the British taxpayer if his new scheme is implemented.

The Prime Minister challenged estimates that it would cost a staggering £18.5billion. But whatever the bill, by Burnham's own candid admission, it will add significant weight to the tax millstone already hung around the neck of every working man and woman in the country.

On Saturday Angela Rayner broke cover – and collective cabinet responsibility – by lambasting Home Secretary Shabana Mahmood for her proposed new policies on permanent residency

Appearing on the BBC's Laura Kuenssberg show, the Prime Minister announced the establishment of a National Care Service, free at the point of use, paid for by everyone

His calculation is they are willing and able to bear that weight. But that was the assumption Theresa May made at the start of her catastrophically ill-fated 2017 election campaign. Like the current Prime Minister, she started that election by pledging a radical transformation of social care. And ended it by pleading 'nothing has changed!'

Then there are the implications of his announcement for the timing of the next General Election. On Friday, the Prime Minister categorically ruled out going to the polls before 2029.

But an hour after Sunday's social care announcement I received a text from a close ally. 'I think it will be in May,' it read.

Downing Street's strategy of getting Burnham to rule out a snap election was to avoid endless speculation that he was going to call one, then being forced to confront a series of headlines accusing him of 'bottling it' if he opted to postpone.

But yesterday's social care pledge has now boxed him in even more tightly. The Prime Minister was clear he was unable to implement the policy immediately because he was constrained by the commitments given in the last Labour manifesto. It would, he vowed, be in the next one.

So what is Burnham expected to do for the next three years? Say to the country, 'I've identified a raft of critical problems, like the social care crisis. I think I've found some solutions. But sorry. You'll all have to sit around and wait for another three years before I get on and deal with them'?

That stance is especially untenable given the strategy recently unveiled by Kemi Badenoch and the Conservatives. In the Tory leader's final PMQs exchange with Burnham, she deployed a new line of attack.

Castigating him for his failure to set out a clear plan for implementing welfare cuts, increasing defence spending, or reversing Sir Keir Starmer's decision to cede sovereignty of the Chagos Islands, she charged: 'He is pretending that he is the change candidate, but the fact is he is still failing to cut welfare, he is still paying to hand over a sovereign territory, and he is still not funding defence. On the issues that really matter, is he not just Continuity Keir?'

If the Prime Minister plans to honour his pledge to wait until 2029 to seek a mandate for serious national renewal, that charge will rightly stick. As Badenoch correctly points out, he cannot spend three years claiming to be the agent of change, whilst simultaneously telling the voters there is nothing to be done because his hands have been tied by his predecessor.

And even if Andy Burnham wanted to engage in 36 months of political procrastination, it's already becoming doubtful his fractious party will let him. One of the charges laid at Burnham's door by his opponents is he has no mandate from the electorate. But within Labour's ranks there are already mutterings about the fact he also has no mandate from his own movement.

On Saturday Angela Rayner broke cover – and collective cabinet responsibility – by lambasting Home Secretary Shabana Mahmood for her proposed new policies on permanent residency. The day before, it was announced that Sir Keir Starmer ally Darren Jones had established a new parliamentary faction aimed at ensuring Andy Burnham remained 'fiscally responsible'.

This indiscipline is, in the view of several MPs, a product of Burnham's messy accession to the Labour throne. 'The fact there was no contest is a problem for him,' one said, 'the view of some people is that if Andy didn't have to play by the rules to get where he wanted to be, why should they?'

Which in turn plays into concern over his dramatic social care announcement. Most Labour MPs instinctively support the plan. 'It's what we need,' one told me. 'It's not new. But we need to make it happen.'

But there is also mounting concern about the wider implications for the party's policy development and wider strategy. 'OK, it's grabbed the headlines,' one Labour insider told me. 'But what process did he follow here? We're told this will form the heart of the manifesto. OK. But you can't publish your manifesto three years before polling day. What will the fiscal situation be in 2029? What will the public mood be? How can you test how this will play in the marginals when you don't even know where the margins are?'

Andy Burnham has told the country there will be no election until 2029. For his sake, he'd better be lying. Because if he isn't, he really has made a rod for his own back.