Newspaper headlines: Boris and Barnier bash May's Brexit plan
Conservative resistance to the prime minister's proposals for Brexit feature on many of Monday's front pages.
According to the Times, 20 Tory MPs have made a joint public commitment to scupper the so-called Chequers deal.
The paper says the rebels - including former ministers Priti Patel and Iain Duncan Smith - have joined the grassroots campaign group StandUp4Brexit.
Boris Johnson's condemnation of Chequers in his weekly column for the Daily Telegraph also makes the paper's front page.
It says that Theresa May faces the start of what is likely to be the most testing period of her premiership as Eurosceptic Tory MPs return from the summer recess intent on destroying her Brexit compromise.
The headline of the i is simply, "May faces fight to keep Brexit plan alive".
The Independent website reports that the number of officials who have left the Brexit department is equivalent to more than half of its total staff.
It says the information obtained by the Liberal Democrats appears to corroborate previous reports about an extraordinarily high turnover there.
Critics now claim it points to "deep instability" at the heart of the government's Brexit operation.
There is shock at National Crime Agency figures showing that up to 80,000 people in the UK pose a threat to children online.
The Sun calls it a staggering number - the equivalent of four packed-out 02 arenas.
"Is any child safe online?" the Daily Mail's front page headline asks.
The paper says web giants and technology companies have the know-how to block offensive material and they must use it - or be held responsible for the vile crimes they facilitate.
Cop shop closures
Figures showing that more than 600 police stations in England and Wales have closed since 2010 make the lead for the Daily Mirror.
It says that, together with the loss of 20,000 police officers, this "sustained attack on policing by an austerity government is unforgivable".
"Crime is rising," the paper goes on, "and the thin blue line must be strengthened in the fight against yobs, thieves, rapists and killers."
The Sun trumpets support for its Stop A Stalker campaign from the Coronation Street star, Kym Marsh - herself a former victim of stalkers.
It urges readers to sign its petition backing a demand by Conservative MP Sarah Wollaston for tougher police powers to deal with the crime.
Writing in the paper, Dr Wollaston says her Stalking Protection Bill would take the onus off victims and allow the police to step in at an earlier stage, before the stalking behaviour becomes deeply ingrained.
It seems that men going through a midlife crisis no longer think of buying a sports car, growing their hair long or flirting with the idea of an extra-marital dalliance.
Instead, the Daily Telegraph reports, these days the key signs of a male midlife crisis are infinitely healthier, such as opting to become a vegan or signing up for marathons.
However, the paper is not impressed by the findings of the research by BUPA Health Clinics.
It hopes that, like dodgy leather jacket wearing, such passions too will pass.
"What's wrong with merely cutting down on one's alcohol intake or going for a gentle jog?" it asks.