EU leaders are set to decide on Friday whether to grant the UK a three-month Brexit extension, the BBC’s Europe editor Katya Adler says.
Most EU nations back it but France “is digging its heels in”, she adds.
So there could be an emergency summit in Brussels on Monday to allow leaders to reach agreement face-to-face.
Boris Johnson insists the UK will leave the EU next week with or without a deal and he will seek a snap election if the EU grants an extension to January.
The prime minister was forced to send a letter to the EU requesting an extension, under legislation passed by MPs last month.
But he said he had told EU leaders his policy was still to leave on 31 October.
Commons Leader Jacob Rees-Mogg told MPs the government “does not want an extension” and was “making every preparation to leave on 31 October”.
Dominic Cummings, Mr Johnson’s chief adviser, is reported to be urging ministers to abandon attempts to get the prime minister’s Brexit deal through Parliament and go for a December election instead.
But some ministers – such as Northern Ireland Secretary Julian Smith – are understood to be urging the prime minister to make another attempt to get his deal through Parliament first.
Cabinet ministers are meeting and are expected to discuss the way forward.