Over the next 48 hours Andy Burnham will not bask in his victory, but disappear from view. ‘He’s going away for the weekend,’ a close friend told me last night. ‘He needs a bit of a break. He hasn’t stopped for months. And he also needs some space to think a little, and prepare himself.’What he needs to prepare for is the fact he is about to become Britain’s next prime minister. The scale of his victory in the Makerfield by-election leaves little room for doubt. Reform were not just beaten, but routed. Restore’s insurgent challenge was squeezed into single figures. The Greens, the Lib Dems and even Kemi Badenoch’s resurgent Tories moved in step behind the King of the North’s march on Downing Street.But as he reflects, there is one thing he should recognise. Before he takes up the reins of office, the country, the Labour Party and Burnham himself require his elevation to be via a proper national contest, not a coronation.I spent a good proportion of the past month in Makerfield. And Burnham’s popularity on the doorsteps was like nothing I had ever seen before. As I wrote a couple of weeks ago: ‘Familiarity, not stardust, is Andy Burnham’s secret weapon in this contest. Half the voters in Makerfield know him. And the other half think they know him.’At the moment no-one, not even the voters of Makerfield, really know what a Burnham premiership will actually mean for them, writes Dan HodgesBut for the moment, that phenomenon remains unique to this constituency. He is from the area. He does send his kids to school here. His new constituents are indeed used to bumping into him in Aldi.That is not something that can be said for the rest of the country. Britain needs some time to be introduced to its new prime Mminister.Then there is the question of his personal mandate. This victory – stunning though it is – was a vote against Keir Starmer as much as it was a vote for Andy Burnham. For the past month Labour MPs canvassing in the seat have been using what one described to me as ‘the Ring doorbell trick’. According to the wily backbencher: ‘Whenever we come up against an undecided we take a moment to check if they’ve got a ring-doorbell. And if they haven’t got the video then we say: “Look, just vote for Andy. And if you do, Starmer will be gone in a couple of months.”’Over the weekend we may get some more pointless bravado from the Prime Minister and the final bitter-enders holding out in the Downing Street bunker. But some time next week he will bow to the inevitable. And when he does it will because the man who secured the endorsement of 10,000,000 people at the last election realises they have now withdrawn their consent for him to govern.Burnham, in contrast, currently enjoys the consent of just 25,000 voters in Makerfield. It’s right their voice should be heard. But it needs to find an echo now. Not solely from the MPs and members of the Labour Party who he is about to lead. But from the country he now aspires to lead.Britain has survived – just – two years of Keir Starmer. It can put up with another few weeks of him while Andy Burnham takes his message round the country in a formal Labour leadership contest. The King of the North must have the chance to make his pitch to Scotland, Wales, the Midlands, the South West, the South East and the rest of his deeply divided kingdom. Keir Starmer failed as Prime Minister because he never really understood why he wanted to be Prime Minister in the first place Because at the moment no-one, not even the voters of Makerfield, really know what a Burnham premiership will actually mean for them. I don’t share the criticism that has been levelled at him during the Makerfield campaign. Where some people saw flip-flopping and evasion, I saw a clever tactical decision to stick to local issues, rather than get dragged into an unwieldy national debate.But now Andy Burnham needs to start to fill in some of the blanks. What is his economic policy? What are his true stances on immigration and Brexit? Where does he stand on foreign affairs and defence?Some of the answers to those questions have to be provided before he takes office. Because if they are not, then he will be in danger of repeating the fundamental mistake that doomed his predecessor.Keir Starmer failed as Prime Minister because he never really understood why he wanted to be Prime Minister in the first place. Or if he did, he never managed to successfully communicate it.To date Andy Burnham has not yet set out why he wants to be prime minister, beyond a (wholly laudable) desire to not be Keir Starmer, to implement some form of as yet ill-defined change, and implement some vague concept known as ‘Manchesterism’.Burnham may well have a cast-iron programme for the governance of the nation clear in his own mind. But if he does, he needs to spend some time sharing it with the rest of us. Because if he doesn’t, he will quickly fall foul of the charge he is making things up as he goes along. And Keir Starmer stands as a stark warning of attempting that.Make no mistake, Makerfield is a stunning personal triumph for Andy Burnham. But politics is a fickle business, and the lustre of his by-election victory will soon fade. And when it does Britain needs to know its new premier secured his crown via a contest, not a coronation.