A former British spy behind a dossier of lurid claims against Donald Trump admitted he was “desperate” to stop him becoming US president, it was alleged on Friday.

Christopher Steele told a US justice official before the 2016 election that he was “passionate” about stopping Mr Trump winning, according to a newly released memo.

Republicans held up the comment as proof the former MI6 agent had “ideological motivations” against Mr Trump that throw into question the reliability of his evidence.

The previously undisclosed conversation was contained in a classified memo written by Republican congressmen that Mr Trump approved for release on Friday.

The four-page document criticises the way the FBI and US Justice Department used Mr Steele’s claims to approve a wiretap on a Trump campaign adviser.

The memo claimed the wiretap request failed to mention that Mr Steele could be politically biased and had been paid more than $160,000 by US Democrats.