Alexander Temerko, a Ukraine-born businessman who has given up to £700,000 to the party, told The Daily Telegraph: “She [Theresa May] is very, very focused on her deal. She says that it is the best deal we can reach. She is wrong.

“We need a new leader of the party who is more flexible, and less stubborn.”

He said he would continue to give money under Theresa May because he supports the Conservative Party rather than the Prime Minister.

He suggested Article 50 would have to be extended and then afterwards “we can find a new Prime Minister and prepare for another election”.

Express