"You can clap now," a Downing Street official with a clipboard instructed the staff eagerly lining the halls of No 10 in the moments before the new prime minister walked in.

The applause duly began before the famous door opened, so the first sight and sound to greet Andy Burnham and his wife were crowds of clapping staff, crammed into the Downing Street hall. They stretched up the long corridor all the way to the door of the Cabinet Room - left ajar for him to walk straight in and get down to work.

I've seen plenty of prime ministers come and go from outside No 10. But I'd never been allowed inside at that moment before, able to hover outside the Cabinet Room and grab a quick word with the country's new leader at such an intense, symbolic time.

I have rarely seen a politician look as thoroughly delighted as Burnham, pride bursting out of his buttoned-up suit - that's right, the T-shirt and bomber jacket didn't make it to No 10 - or a leader who has wanted to stop and shake as many hands.

No 10 staff are already wondering if they'll ever be able to stick to a regular prime minister's schedule, normally designed with military precision. If Andy Burnham was able to take the time to stop and speak to everyone in the country, I suspect he probably would.

It's a sign of his different style that our team was given permission to be behind the scenes at three key moments in the 59th prime minister's first week in charge - when he became Labour leader, when he walked into No 10, and on day one at his new Manchester outpost, No 10 North.

Most important by far was our half-hour interview in that shiny new office, after weeks during which Burnham was chased by accusations he'd avoided tough questions. But the extra glimpses we were given, alongside Burnham's own voracious appetite for social media, display a prime minister that's not just at ease in front of the cameras, but a leader who wants to bring you along for the ride.

They included revealing moments that are normally hidden - his first steps into the Cabinet Room to appoint his team, rating pub snacks with his Chancellor, John Healey, in an Instagram post, external, and sharing pictures with us of the family dog, Axel, whom he describes as having "angry little man energy".

"Comms" - how politicians communicate and explain themselves and talk to the public - is not the be-all and end-all.

Burnham's exploits online have already brought mockery and launched a thousand memes. But if a leader can't get your attention to make their arguments - as Keir Starmer found so challenging - ultimately, they are not going to get very far at all.

And the biggest difference of the Labour reboot so far is how the government looks and sounds. They've put an obvious priority on punter-friendly announcements such as cutting VAT from energy bills and tax breaks for pubs - although it is important to note the details on how to pay for all of that are not yet clear.

For Burnham though, telling his story is the easy part. Joking about the unique stink that accompanies Scampi Fries, or showing me his gold disc on loan from The Smiths' guitarist Johnny Marr, won't help him deal with US President Donald Trump, find money for defence, or create a new service to care for the elderly and vulnerable in England. Nor will it be any use as he grapples with the country's huge debts, changing demographics or public concerns about immigration.

Listening carefully during our interview, it seemed Burnham had distinct gears. He was fluent and passionate on his familiar ground: his desire to sort out social care, his track record in Manchester, his desire to run a government that feels relevant and effective where you live, local leaders eager to make many more decisions and able to spend taxpayers' money more freely without permission from Whitehall.

Those are his core beliefs, arguments he's made hundreds, if not thousands of times.

But when it comes to how he'll apply what he thinks in principle to what he does in practice, that was not always so clear. On social care for example, he's long believed there ought to be a National Care Service, like the NHS. But in a speech on Wednesday, that's not likely to be what he unveils.

Instead, he told me he'd "brought it straight forward", understood to mean speeding up the government review by Baroness Louise Casey of what ought to be done, not saying, "here's the plan".

When it came to questions that are on his desk for the first time, there was a contradiction. Burnham told us all many times that he will stick to the manifesto the country voted for in 2024.

But he's also vowed his arrival in office will usher in the biggest change in four decades. You don't have to be a student of political history to find a mismatch there - he's going to stick broadly to Sir Keir's plan, yet shift the government more fundamentally than leaving the EU, or the financial crash? Really?

And beyond the rhetorical tension in several areas, Burnham gave clear indications that he will apply "new eyes". Will he stick to the home secretary's plans to make migrants wait 10 years or more before they can permanently stay in the UK? He's looking at that again he told me, and hinted that care workers could possibly be exempt.

What about welfare? Remember Sir Keir ditched most significant reforms in the face of resistance on the back benches. While seeking not to "blame" anyone receiving benefits, Burnham said the country had to "get serious" about getting the welfare bill down, and suggested he might make it harder for some people to claim, by imposing extra conditions.

He didn't want to give much away about where he was going to find extra billions for defence, or pay for public services. He repeated that he'd stick to the promises on income tax, VAT and National Insurance made in 2024. But the prime minister clearly pointed to a possible shake-up of the council tax system, where those with the most expensive properties might have to pay considerably more. Changes like that to council tax, or to welfare, would be huge political moves that would put him on a collision course with some of his party, and some political opponents too.

Then, when it comes to matters of war and peace, which for Burnham are genuinely new, it felt we could see him thinking in real time how to answer the question, perhaps trying to balance giving a flavour of who he is, without creating a political accident.

Does he trust Trump? Twice he wouldn't say.

"It's a changing world," his second answer.

Would he take a call from Russian President, Vladimir Putin?

A pause, then: "I'd have to know the circumstances".

As mayor, Burnham evidently spent years thinking hard about how to use power, and how he wants to shift the balance in the UK away from Westminster. The impact of that stance could be profound, way beyond some admirably shiny No 10 signs emblazoned all over one floor of a government building in Manchester.

Mayors are expected to get power to spend nationally collected income tax, and crucially to spend billions without strings.

Burnham spent time too as mayor absorbing people's experiences, their hardships and frustrations.

"My strength always is in remaining close to people, close to the public, that will not change because I am prime minister," Burnham told me.

Although don't be in any doubt, he also spent time thinking and planning about how to make a return to the political heart of this country, the Westminster he believes is so flawed.

But when it comes to the gravest matters that prime ministers have to deal with - security, power around the world, or the country's long-term economic stability, we're perhaps yet to see if Burnham's ambition for No 10 is accompanied by truly new big ideas that match the scale of his rhetoric.

There are worries on the right of the Labour Party that Burnham has not absorbed the reality of the country's economic position - years of stuttering growth, and sky-high levels of debt that leave the UK incredibly vulnerable to the financial markets' judgements, whether he likes it or not.

And concerns on the left, that he's tickled their bellies with promises of "authentic Labour", flirting with the ideas of increasing state control of vital industries, but which might not come through. And like most incoming prime ministers, he has precious little experience of handling international events. The moments in our interview where he was least sure-footed were answering questions about how he'd manage relationships with Donald Trump and Vladimir Putin.

One minister said he'd "vibe left, but govern from the centre". Perhaps, as he's tried to give firms and families a "breathing space" when it comes to the cost of living, he'll ask for "breathing space" from the public before his complete programme becomes clear.

Burnham has long been unusual as a politician - a leader who has managed to be popular in a time when politicians often disappoint and are sometimes despised. He knows he's walking into a job that's been marked by failure for a decade. As he told me, "the onus is on me not to be another one who just doesn't change things". He's part of a political generation he proclaims to be "just not good enough".

Remember, his own career has had plenty of failure too. It took Burnham three goes to become the leader of his party. As he arrived, straightening his tie, to be confirmed in the top job in central London 10 days ago, I asked him why he'd taken so long.

He laughed and told me, "I like to make an entrance".

Andy Burnham has now truly arrived. But he knows all too well, there won't be applause everywhere he goes.

Watch Panorama Andy Burnham: The Laura Kuenssberg Interview on iPlayer from 06:00BST, and on BBC One at 20:00BST on Mon 27 Jul 2026.

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Top picture credit: Reuters