Newspaper headlines: 'Secret' Brexit bill, and Tory rebels warned - BBC News
The Sunday Times says Theresa May has "secretly agreed" a £50bn sum to settle the UK's Brexit bill.
According to The Sunday Times, the outcome of the general election may have cost the country about £20bn. A source, described as a close ally of of Theresa May's, explains that meeting the UK's obligations to the EU had been estimated at up to £30bn. But, it says, the weakening of our negotiating position because the Conservative government lost a majority means the cost will rise.

The Mail on Sunday says the Prime Minister is hoping to keep the details of the likely "divorce bill" a secret until after the Conservative conference. Otherwise, it says, there could a furious backlash from Conservatives opposed to the EU.

The slow pace of the Brexit talks doesn't impress The Sunday Mirror. It calls on the EU to come up with a figure so Brexit Secretary David Davis can make the arguments for reducing it.

The Sunday People, among others, reports that government whips are at work trying to persuade "wavering Tory MPs" to support Mrs May's approach to Brexit. The Sun on Sunday says some have complained of "bullying". And The Observer believes the attempt to promote unity has left her facing "a growing Tory revolt over her leadership."

The Sunday Telegraph warns the rebels that blocking Brexit would undermine democracy and respect for our political class. Rather than do that, it urges anti-Brexit MPs to "put country before conceit".

Thousands of children going back to school this week could face an epidemic of bullying online, according to The Sun. It welcomes the training of more teachers to support pupils and combat the threat of cyber abuse. But the paper calls for more to be done - if the 8m children at risk are to be protected from a torment that doesn't stop at the school gates.

For several of the papers the main news is the ructions that have followed the arrest on suspicion of drinking and driving of the former England captain, Wayne Rooney. The People believes he is fighting to save his marriage. The views of his wife Coleen are forcefully delivered elsewhere. The Sun calls her "furious". The headline in The Mirror is "how could you do this to me when I'm pregnant?".

This autumn, says The Sunday Express, could turn out to be warmer than the summer. It says forecasters think hot air from Europe, and balmy air from the Atlantic, could combine to produce temperatures of 32C (89.6F). "How typical," says the paper, "that the sun should start shining as soon as the school holidays are over."

Britain must prepare itself for "invasions of growing numbers of foreign sea creatures" due to climate change, The Observer says. The paper says the experts believe that warming waters will drive some of our currently native species of mussels, fish and oysters further north. Their places may be taken by red mullet, john dory and pacific oysters, forcing us to change our seafood diet.