Labour's leadership struggles are the focus of Sunday's papers. Keir Starmer could announce his departure date as early as tomorrow, a Labour MP has told the Telegraph.

Starmer is expected to resign on Monday, the Observer headlines on. According to the paper, the prime minister "accepts his position is no longer tenable".

Meanwhile, the Sunday Mirror headlines on the "historic royal move" by King Charles in releasing his personal tax return - Britain's first monarch to do so in modern times.

It is 09:00 BST, meaning Sunday with Laura Kuenssberg is starting now.

On today's programme:

• Business Secretary Peter Kyle
• Shadow chancellor Mel Stride
• Former adviser to Keir Starmer, Paul Ovenden
• Former Cabinet Secretary Lord Case
• Former Defence Secretary Lord Hutton

The show's panel will also be giving their insights, with Labour MPs Jess Phillips, Toby Perkins and Luke Charters joining.

We will be bringing you text updates from the programme over the next hour and you can also watch live at the top of this page.

Keir Starmer has been making time this weekend to "reflect on the political realities" that he finds himself in, the business secretary says.

Peter Kyle tells Sky News' Trevor Phillips that he had a "frank" conversation with the prime minister on Friday.

He says that both of them have been reflecting in their own ways about what "putting country first" means in the current moment.

Kyle adds: "He is, as well as working really hard over this weekend, I think he is making time to reflect on the political realities, challenges and opportunities that he finds himself in."

We will shortly be hearing from the business secretary on Sunday with Laura Kuenssberg, which you can watch live at the top of this page from 09:00.

Image source, EPA/Shutterstock

• Calls for Keir Starmer to set a timetable for his resignation have escalated after Andy Burnham led Labour to victory in Thursday’s Makerfield by-election, a win which the newly elected MP said was an "opportunity to turn the tide… make the country feel like it's working again"

• Elsewhere, the Scottish Conservatives won their first Westminster by-election in more than 50 years in Aberdeen South, while the SNP retained Arbroath and Broughty Ferry by over 5,000 votes

• Under-16s in the UK will be banned from using social media by spring next year, Starmer announced, following a government consultation in which 89% of 9,499 parents and carers said they strongly supported a legal minimum age for social media access
• Starmer also attended France's G7 summit this week, saying that the UK will play its "full part" in getting the Strait of Hormuz reopened "as soon as possible", before Iran said on Saturday it had closed the waterway ahead of fresh talks with the US
• The government's proscription of Palestine Action as a terror organisation is lawful, the Court of Appeal has ruled, overturning an earlier decision from the High Court that the ban had breached the right to protest and had been incorrectly taken by ministers
• Green Party leader Zack Polanski has been cleared by the Greater London Authority following a complaint over his failure to pay council tax on a houseboat in Hackney, with a monitoring officer saying that "no further action" was needed and the case had been closed

Image source, Reuters

Keir Starmer has been adamant that he is "not going to walk away" from his role as prime minister. And No 10 this morning says he's getting on with the job.

However, should his position change, Starmer could choose to stay in post during a transition period before handing over to a successor, who would be both Labour leader and prime minister.

If Starmer chose to resign with immediate effect, a member of the cabinet would replace him in a caretaker capacity.

This would involve a decision by the cabinet, which would consult with Labour's National Executive Committee. Deputy Prime Minister David Lammy would not necessarily fill the caretaker role.

A leadership contest would then follow.

In this scenario, each potential challenger would need support from 20% of the party's MPs and to be backed by either 5% of constituency Labour parties, or at least three affiliated organisations - of which two must be affiliated trade unions.

Laura Kuenssberg
Presenter, Sunday with Laura Kuenssberg

Image source, Reuters

"We promised people we weren't going to do this."

There is exasperation in the voice of a long time Labour adviser. But as every hour passes, it is more likely the UK will soon have its seventh prime minister in 10 years.

Talk of Sir Keir Starmer fighting is fading, his exit seems more likely as the weekend goes on. The prime minister is at his country retreat, Chequers, spending time with his wife.

The man coming for his job, Andy Burnham, is spending the weekend with his family, away from home too.

Several sources told me Starmer really does believe he could beat Burnham in a leadership contest, and concluded that a fortnight ago after watching him on BBC Question Time on a Thursday, then failing to explain the borrowing and spending rules in a Newsnight interview on the Friday.

A government insider said: "On Saturday he phoned his closest allies and said, 'I'm sure I could win'."

But the widespread assumption this weekend in the party is that Burnham would beat him hands down, and another government source said "it's nuts" to imagine the PM could come out on top.

An increasing number of ministers, previously loyal to Starmer, now think it's time as one cabinet source told me they "wouldn't want the prime minister to humiliate himself" in a race.

The chances of him staying to fight are diminishing. But what is still a mystery this weekend is exactly how Starmer will respond.

• Read more: Talk of Starmer staying on to fight is fading - fast

Leadership uncertainty is "enormously disruptive" and presents a "big challenge" for the government, a former cabinet secretary has said.

Simon Case, the UK's highest-ranking civil servant from 2020 to 2024, tells the BBC's Sunday with Laura Kuenssberg that political upheaval also "costs us money" by driving up borrowing costs.

His comments come after Andy Burnham won Thursday's Makerfield by-election, paving the way for a Labour leadership challenge.

Prime Minister Sir Keir Starmer is now under pressure from cabinet ministers and a growing number of MPs to set out a plan for his departure, and avoid the need for a leadership contest.

• Read the full story

As we've just reported, No 10 is steadfast in its message: Starmer is getting on with the job.

Downing Street's reiteration of the PM's position follows reporting in The Observer that Starmer is expected to resign on Monday and set out an orderly exit.

The news outlet cites a source as saying: "He’s come up hard against the reality that the support isn’t there... the truth is everyone knows this is no longer a tenable proposition. There’s a sadness about it all, of course, but sometimes there’s just an inevitability in politics and as Boris Johnson said, 'When the herd moves it moves'."

It adds senior Labour figures believe a “clear statement” could come as early as Monday.

The BBC has not independently verified the reports.

Nick Eardley
Political correspondent

The line from No 10 this morning is that their position hasn't changed from Friday - when the prime minister vowed to fight on.

Downing Street says Keir Starmer is getting on with the job.

But we know a growing number of people are urging the prime minister to set out a timetable for his departure - all the way up to cabinet level.

An increasing number of people loyal to the current prime minister are concluding the game is up.

Nothing is confirmed yet. It's not over until it's over.

But the next 24 hours could be extremely significant.

Matt Spivey
Live editor

Image source, Reuters

It's that time of the week again.

Laura Kuenssberg is set to question key political players after a gruelling week for Prime Minister Keir Starmer.

Andy Burnham's big win in the Makerfield by-election on Thursday night paved the way for his return to Parliament, and he's heavily tipped to stand a chance at getting the top job.

Following the former Greater Manchester mayor's victory, Starmer vowed to stand in any leadership race and called on the party to "pull together".

The PM faces mounting pressure from cabinet ministers and a growing number of MPs to set out his plan for an "orderly transition".

Downing Street said on Sunday morning that the prime minister was "getting on with the job" and that his position of being "determined to fight for his job" had not changed.

On this week's show, Business Secretary Peter Kyle and shadow chancellor Mel Stride will take to the hot seat.

We'll also be hearing from former Starmer adviser Paul Ovenden, former Cabinet Secretary Lord Case, and former defence Secretary Lord Hutton.

You can watch the programme live at the top of this page from 09:00 BST and we'll bring you the key developments.