The Sunday Times says Theresa May is to tell Conservative MPs to back her EU withdrawal agreement this week, or risk no Brexit at all.
According to the paper, the prime minister will warn Tories that a failure to support her could lead to a "Hotel California Brexit" - where, in the words of the Eagles, "you can check out, but you can never leave".
The Sunday Telegraph reports that Mrs May's team spent Saturday negotiating with leaders of the DUP "over a two-part plan to win their support".
Arlene Foster and Nigel Dodds are said to have received a guarantee that the EU will not treat Northern Ireland and Britain differently in terms of the customs union and single market after Brexit.
They also got a promise that Democratic Unionist MPs will be deeply involved in the UK negotiating team over the future trade deal with Brussels, the paper says.
A leaked document - seen by the Observer - suggests the EU is preparing for the fall of Theresa May, "amid a complete collapse in confidence in the prime minister".
Brussels is understood to fear there is little hope she will succeed in passing her deal, and is preparing itself for a change of the guard in Downing Street.
Photographs of Mucad Ibrahim - the youngest victim of the New Zealand mosque shootings - feature in several papers.
The Sunday Mirror says the three-year-old was "mown down running for his life" as a white supremacist went on the rampage, killing a total of 50 people.
In a joint article for the Sunday Times, the former integration tsar, Dame Louise Casey, and the former national police counter-terrorism leader, Sir Mark Rowley, warn that efforts to stop extremism are being "undermined at every turn".
They argue both white working-class and British Muslim communities are marginalised, making them highly susceptible to extremist narratives, and say there must be "much more backing" for the government's Prevent programme.
They also call for much less tolerance of intolerance in the "Wild West" of the internet and social media.
The Mail on Sunday says the BBC has been accused of allowing its Comic Relief charity appeal to become an advert for Jeremy Corbyn.
Conservative MPs are said to have "reacted with fury" as celebrities taking part in Friday's fundraiser "painted a bleak picture of deprivation in the UK".
The former Tory leader, Iain Duncan Smith, is quoted accusing Sir Lenny Henry of peddling "socialist nonsense" after the comedian told viewers "real hunger" was hitting a "huge number" of British children.
The BBC has told the paper that the six-hour broadcast included films which demonstrated the depth and range of many projects and issues supported by Comic Relief - both in the UK and abroad.
Meanwhile, the Sunday Times links a fall in donations to the appeal to a row about so-called "white saviours".
It says the final total on Friday was £8m down on the amount raised at the end of the previous show - after the Labour MP, David Lammy, criticised Stacey Dooley for posing for a photograph with a Ugandan child while she made a documentary.