Mundell said: “I will support Ben Wallace if he stays. His decency and integrity is not in question. We have had too much drama lately and he is in an ideal position to lead a quiet and competent period of leadership.
“I don’t imagine there will be any figures that come out clearly favored by all Scottish Conservatives, but I think Ben’s background story of working across the UK will appeal to our members.
“We joined the Scottish Parliament together in 1999, he has served in the Scottish Guard and his family is from Scotland. Then he has had a very successful career south of the border and has been excellent in all ministerial posts and of the cabinet he has occupied.
“Ben is not someone who has had a leadership campaign in the shadows for months and now has to assess the situation. But a lot of people are encouraging Ben to stand up, and I’m one of them.”
Douglas Ross, the Scottish Conservative leader, has so far refused to publicly support a candidate to take over from Johnson.
John Lamont, MP for Berwickshire, Roxburgh and Selkirk, has suggested he will support Trade Minister Penny Mordaunt.
He said: “There are a number of strong candidates, but the person who has continuously impressed me during my time as a Member of Parliament and before as an MSP is Penny Mordaunt and I think she is a very effective, very strong communicator with the Union. . ”