Some of British Prime Minister Theresa May's ministers will demand a "Plan B" on her Brexit proposal next week and could quit if she does not change course, the Telegraph newspaper reported late on Friday, citing unnamed sources.

Ministers will demand an alternative plan to her "Chequers" proposal at a Cabinet meeting on Monday, the Telegraph said.

That plan had already been savaged by European Union leaders in Salzburg earlier in the week, prompting May to defiantly challenge leaders of the bloc to come up with its own plans.

Pro-Brexit members of May's party on Friday had welcomed her defiant tone, but her Chequers proposal has many domestic critics, too.

The Telegraph said there was "speculation" that work and pensions minister Esther McVey might walk out of Monday's meeting if no new proposal was presented, while international development minister Penny Mordaunt was also tipped as a possible resignation candidate, though the newspaper said friends denied she would resign.

Earlier on Friday, Mordaunt said that the EU's attitude was increasing support within Britain for an exit from the bloc, even if it meant leaving without a deal.

The Telegraph said Sajid Javid, the interior minister, favoured a deal that would make it easier for Britain to sign trade deals, but was unlikely to quit.