Newspaper headlines: Brexit divisions and helpline for 'hero' troops
Many of the papers focus on the latest twists and turns in the Brexit saga.
The Sunday Mirror says the UK is in "a mess" over it - "a maze in which we are lost" - "a pickle we must sort out".
Not since World War II has Britain needed political bulldogs so much - the paper says - but instead "we've got rabbits frozen in the headlights of indecision".
It concludes with a warning that "today's chaos could lead to tomorrow's catastrophe".
Whereas the Sunday Express is more optimistic, saying that Theresa May's forthcoming speech in Brussels this week will be a "patriotic" address in which she'll insist Britain's "best days really do lie ahead".
It says Mrs May will lay out an "ambitious" vision of what the UK's future economic partnership with the EU should look like, following Thursday's Brexit summit of senior ministers at Chequers.
But according to The Mail on Sunday rebel Tory MPs are planning to ambush Mrs May, by forcing a debate on the government's intention to leave the customs union after Brexit.
The issue - writes columnist Dan Hodges - is one Downing Street is not willing to accept defeat on under any circumstances.
But it could, he says, ultimately leave Tory backbenchers who want a so-called soft Brexit with a stark choice between sticking to their principles - and forcing a general election - or standing by their leader.
The Observer's chief political commentator Andrew Rawnsley says the government's business managers are in a panic as they try to give Tory whips more time to try to get potential rebels to fall into line.
He says the chance to defeat the government on the issue of the customs union appears to be the reason why Jeremy Corbyn's "watery position" on Brexit seems to be evolving.
'In the nation's interests'
Writing in the Sunday Telegraph the minister for the cabinet office, David Lidington, warns the devolved administrations not to undermine Westminster's negotiating position by seeking separate powers after Brexit.
Singling out the SNP, Mr Lidington says any attempt by Holyrood to seize control of key trade powers from Brussels would result in a "disjointed" economy and leave Britain struggling to make its way in a new world outside the EU.
Elsewhere, the UN Security Council's unanimous vote to approve a 30-day ceasefire in Syria is highlighted.
Under the headline "Syria's Endless Agony", the Observer carries a picture of two tearful Syrian children, their faces smeared with blood and dirt.
They were photographed at a makeshift clinic in Eastern Ghouta, the besieged district outside Damascus that's been bombarded by pro-government forces, where nearly 500 people have died in the last week.
The paper says Russia's delaying of UN action underscores the unrepentantly outlaw nature of Putin's leadership. But it is also scathing of the US administration, claiming Donald Trump "cares not a fig for dying Syrians - but does want to stay pals with his Russian buddy."
It concludes that the future of collective global governance is looking bleak.
The Mail on Sunday claims a "stunning victory" for its Helpline For Heroes campaign.
Writing in the paper, Defence Secretary Gavin Williamson says he has agreed to spend an extra £20m over the next 10 years to fund the service, and other new mental health initiatives, to reduce the rate of suicides among troops and veterans.
Mr Williamson describes the armed forces as the very best of British - who deserved nothing less than the very best support.
And finally, the Sunday Times reveals the story of a former British diplomat who escaped prosecution in the 1950s, after he apparently confessed to spying for the Soviet Union.
The paper says David Floyd - who died in 1997 - admitted passing information to Russian intelligence agents while based in Moscow at the end of World War II.
He went on to become the communist affairs correspondent of The Daily Telegraph and "one of Fleet Street's most knowledgeable Kremlinologists".