Keir Starmer insisted he had not been a failure as Prime Minister today – before he headed to see the King to officially resign.
The outgoing premier gave a farewell address outside the famous black door of No10 this morning, just two years after winning an extraordinary election landslide.
Sir Keir declared he was 'closing the book' on his time in Downing Street, before he added that his 'work is done' and insisted the country is 'stronger' than it was before he became PM.
He insisted Andy Burnham – who orchestrated a coup to secure the leadership – would have his 'full support' as his replacement.
'I go with good grace, I go with a smile and I go proud of everything we have achieved,' Sir Keir said, thanking wife Victoria and his family.
Close Cabinet allies including David Lammy and Rachel Reeves had gathered with hundreds of aides in a sunny Downing Street to watch Sir Keir say goodbye.
London mayor Sadiq Khan was also present for the emotional moment.
Buckingham Palace confirmed shortly afterwards that Sir Keir had officially resigned after 745 days as PM, leaving a vacancy that was immediately filled by Mr Burnham.
The former Greater Manchester mayor became the seventh PM in just a decade after his own audience with the King at lunchtime.
Keir Starmer's resignation as Prime Minister was accepted by the King at an audience in Buckingham Palace
The outgoing PM spent around 30 minutes at the Palace as he ended his premiership
Sir Keir earlier gave a farewell address outside the famous black door of No10, just two years after winning an extraordinary General Election landslide
Close Cabinet allies including David Lammy and Rachel Reeves had gathered with hundreds of aides in a sunny Downing Street to watch Sir Keir say goodbye
During his farewell speech, Sir Keir declared 'my work is done' and insisted that the country is 'stronger' than it was before he became PM
There was a hug for Chancellor Rachel Reeves - also expected to lose her job - after the speech
Sir Keir and his wife, Victoria, got into a car to be driven to Buckingham Palace after his Downing Street address
Sir Keir gave Lady Starmer a kiss as they left Downing Street for the final time
In his valedictory statement, Sir Keir said: 'I am about to visit His Majesty The King to offer my resignation and close the book on my time as Prime Minister.
'My work is done. In six and a half years, I took our party from a historic defeat in 2019, changed it so it was fit to face the country and won a landslide general election victory in 2024.
'Since then, it has been the privilege of my life to serve you and this great country as Prime Minister, and I am confident that Britain is now stronger and fairer than it was two years ago.
'Our economy is stronger. Our public services are on the up, with the biggest fall in waiting times for 17 years. Children are being lifted out of poverty every single day.
'Immigration is down significantly. Our defence and security are on a far stronger footing and our international reputation is greatly enhanced.
'Yet the thing I will always take away with me, the most humbling aspect of this job, is the front row seat you get to witness the greatest things of this country in action. To see, every day, immeasurable acts of resolve, grit, decency and compassion.
'From people who serve our country, whether that's in their regimental colours, NHS scrubs, or simply the millions of people in their communities who volunteer their time and their effort to the ground beneath their feet.'
After paying tribute to his family and his top staff, Sir Keir added: 'For all the focus on individuals, politics will always be a team sport. And the changes we've delivered for our country and our party belong to everyone who has fought for them. I thank them again today.
'And I thank the British people for the opportunity to serve. I go with good grace, I go with a smile, and I go proud of everything that we have achieved. Thank you very much.'
The handover comes barely a month after Mr Burnham returned to Westminster following his victory in the Makerfield by-election.
He has been installed by Labour MPs in a 'coronation', without a formal vote by activists – or having to spell out any policies.
Among the vague commitments laid out by the incoming PM so far are devolving power away from Westminster.
He has announced he will scrap Sir Keir's flagship digital ID programme to focus money and attention on the cost of living.
In an interview with The Times, Mr Burnham said he had already spoken to the Treasury about his planned announcements and stressed the importance of making people 'feel better'.
Adding that complaints about frozen tax thresholds had been 'lodged in his mind' since the Makerfield contest, he said: 'So when people, they're just characterising me as a tax raiser, well again, it's never that simplistic is it? The breathing space point is a really serious one.'
The comments raise more questions about how Mr Burnham will pay for giveaways, after he backed a 'land tax' and harked back to the 1970s, condemning Thatcherite reforms.
But the weekend was dominated by bungled briefing over whether the new Government will allow new oil and gas drilling in the North Sea.
The leader's team has now confirmed he will stick to Labour's 2024 manifesto, which promised not to issue new licences.
Instead he could merely allow expanded drilling at the Rosebank and Jackdaw sites – something that was being considered by Sir Keir's administration.
That could bode badly for Mr Burnham's relations with Donald Trump, who yesterday hailed further drilling as a way of preventing Britain from being a 'poverty-stricken disaster'.
Andy Burnham became the seventh PM in just a decade after his own audience with the King at lunchtime today
Mr Burnham also faces a decision on whether to temporarily nationalise Thames Water as the firm struggles with a £20billion debt pile.
He has already expressed support for greater public control of essential services, and Thames Water's main creditors have said they are willing to discuss the issue with his new ministers in an effort to agree a rescue deal and avoid the business falling into a so-called 'special administration regime'.
Another priority is likely to be reforming social care, which he has said is something he wishes to 'expend political capital' on.
Liberal Democrat leader Sir Ed Davey has urged Mr Burnham to engage other parties to solve the 'social care crisis', calling for guaranteed rights for family carers, a universal safety net and protection against 'catastrophic costs'.
Tory leader Kemi Badenoch has also written to Mr Burnham, saying her party will work with him to cut the welfare bill and calling for him to rule out tax rises and back new oil and gas drilling.
Mrs Badenoch told Mr Burnham she would 'never shirk' from holding him to account, adding: 'You will enter office without having set out a clear plan on any of the issues facing our country.
'You have refused calls to come to Parliament for questions from MPs, and you have not submitted yourself to serious media scrutiny. This is not a promising start.'
The famous black door of No10 was given a buff-up ahead of the changeover of premiers
Kemi Badenoch warned Mr Burnham he will have to cut spending instead of increasing taxes
In full: Keir Starmer's final speech as PM
Today I am here to offer my resignation and close the book on my time as Prime Minister. My work is done.
In six and a half years, I took our party from a historic defeat in 2019, changed it so it was fit to face the country and won a landslide general election victory in 2024.
Since then, it has been the privilege of my life to serve you and this great country as Prime Minister.
I am confident that Britain is now stronger and fairer than it was two years ago.
Our economy is stronger. Our public services are on the up, with the biggest fall in waiting times for 17 years.
Children are being lifted out of poverty every single day. Immigration is down significantly. Our defence and security are on a far stronger footing. And our international reputation is greatly enhanced.
Yet the thing I will always take away with me, the most humbling aspect of this job, is the front row seat you get to witness the greatest things of this country in action. To see, every day, immeasurable acts of resolve, grit, decency and compassion.
From people who serve our country, whether that's in their regimental colours, NHS scrubs, or simply the millions of people in their communities who volunteer their time and their effort to the ground beneath their feet.
We face a world now where our enemies will stop at nothing to divide us because of our values, our freedom, our decency, and frankly, because of our unflinching resolve towards the brave people of Ukraine.
And so under this attack, it is vital that we remember the greatness of the Britain all around us, that while we debate how to fix our problems, there is something we inherit from our country and our character that can give us confidence that we can change our country for the better; that we can create a Britain where every child can go as far as their talent will take them.
And we can unite different people under our common flag if we don't succumb to that division.
So, as I now pass the baton to Andy Burnham, I wish him every success. He has my full support.
And finally, I want to thank once again my family, Vic and our children, my team, all the staff here and across the Labour Party, everyone at Number 10 and across the civil service, and everyone who has supported our efforts along the way.
For all the focus on individuals, politics will always be a team sport. And the changes we've delivered for our country and our party belong to everyone who has fought for them. I thank them again today.
And I thank the British people for the opportunity to serve. I go with good grace, I go with a smile, and I go proud of everything that we have achieved. Thank you very much.