THERESA May was likened to the captain of the Titanic last night amid mutiny over her Brexit blueprint.

At least three ministers are ready to quit over the PM’s proposed deal for leaving the EU.

Boris Johnson’s brother Jo warned colleagues were “thinking very hard” about their futures after he became the sixth Government member to quit over the issue.

But defiant Mrs May is pushing ahead with a plan which 51 Brexiteers and eight Remainers have vowed to vote down. She had hoped to seek Cabinet approval this week but a source admitted things were “a bit gummed up”.

A Cabinet insider said: “She’s like a ship’s captain who can see an iceberg ahead but won’t change course, even when members of the crew leap overboard.”

All eyes are on Brexit Secretary Dominic Raab and Attorney General Geoffrey Cox, who is fully on top of the legal implications of signing up to it.

Commons Leader Andrea Leadsom, Aid supremo Penny Mordaunt and Work and Pensions Secretary Esther McVey are said to be unhappy and considering their next move.

Last night a key proposal by the PM for an “independent mechanism” for deciding when the UK could leave a customs union was rejected by EU officials. A Whitehall source told The Sunday Times the plan had been May’s “life-support machine” and added: “By rejecting the proposal, the EU has just turned off the oxygen.”