Boris Johnson’s willingness to pursue a no-deal Brexit has driven one of his biggest business backers to throw his weight behind his “more pro-business … and much more heavyweight” rival Jeremy Hunt in the race to become the next prime minister.

Mr Johnson’s claim to be willing to take Britain out of the European Union “at any cost” by the end of October had breached a “hard red line” for Mr Temerko in whom he could support.

Mr Johnson had “the wrong plan” for Brexit, and his failure to agree a better deal in Brussels would force him to pursue a “dreadful” no-deal Brexit – an outcome that Parliament would stop and leave him at at a similar impasse to Theresa May.

On Thursday, Alexander Temerko also told Sky News that he will call on business to support Jeremy Hunt campaign to be the next leader of the Conservative Party.