FILE PHOTO - Former British Foreign Secretary Boris Johnson gives a speech at the JCB Headquarters in Rocester, Staffordshire, Britain, January 18, 2019. REUTERS/Andrew Yates

LONDON (Reuters) - The United Kingdom needs to secure changes to Brexit deal’s Irish border backstop such as a time limit and an exit mechanism, former Foreign Secretary Boris Johnson said on Monday.

“Some of the ideas that the prime minister has mentioned in the House do seem sensible,” Johnson, one of Britain’s most prominent Brexit campaigners, told BBC radio. “I think you would need a time limit.”

“I think I would want to look very carefully at what was being proposed and it would have to give the United Kingdom a UK-sized exit from the backstop,” he said.

When asked, he did not specify that the backstop had to be removed entirely: “The most promising way forward is to do what is called the Malthouse compromise. The exciting thing about this is that it actually has the support of colleagues on both sides.”

(This story was refiled to add source in headline)