Speaking on the eve of the Tory leader's high-profile visit to Rwanda to visit Conservative MPs taking part in aid projects, Miss Widdecombe cast doubt on the value of Mr Cameron's "photocalls".

She told the Mail on Sunday: "We must not lose our nerve, and there is an underlying goodwill towards David Cameron. He has been very successful in getting support from people who previously would not have looked at us. But he must now pay a great deal of attention to shoring up our traditional vote.

"People want us to produce firm and clear policies on issues that worry them most - law and order, immigration and the health service.

"There is nothing he can do in a few days that should stop him going ahead with his visit to Rwanda - and some of his photocalls have been very effective in the past. Having said that, I'm not sure that many voters know where Rwanda is."

Right-wing MP David Davies told the paper: "David Cameron has produced excellent policies on the environment and equality, but we must also ensure that people know we are the party that still believes in strong policies on crime, immigration and the creeping takeover of Britain by Brussels."