Former foreign secretary and staunch eurosceptic Sir Malcolm Rifkind is to back Mr Kenneth Clarke in the battle to lead the Tory Party in Britain.
His backing will help Mr Clarke in his bid to win support outside the relatively narrow pro-euro faction of the party.
Sir Malcolm had originally backed Mr Michael Ancram, who has now joined the camp of Mr Clarke's rival, Mr Iain Duncan Smith.
But Conservative vice-chairman Mr Steven Norris says there is a danger the Tories could find themselves caught "between a rock and a hard place" in the leadership battle.
Speaking on the Sunday with Adam Boultonprogramme on Sky News, he said: "I've certainly made it absolutely clear that I think if we lurch off to the right we might as well pack up and go home because frankly there won't be a lot of people around."
"When I look at some of the people around Iain [Duncan Smith], I'm one of those who can happily say I think he's a splendid chap personally, because I do . . . but I think some of the people around Iain worry me, they will worry a lot more people than me.
"Kenneth on the other hand is a genial wrecker if he's not careful. We all love him, terrifically affable sort of chap but capable of doing enormous damage because it's not just the euro, it's the euro and a whole lot of other European issues that I'm sure Mr Blair will arrange to have on the floor of the House every single week," he said.
PA