Matt Hancock has said Suella Braverman and her right-wing fanclub could be the Tory "Corbynistas" who tear the party apart.
He claimed the party will be "finished" if the National Conservatism movement - which held its first UK conference this week - prevails.
Mr Hancock - who was stripped of the Tory whip after jetting off to take part in I'm A Celeb last year - said he was alarmed by the "Trumpian takeover" that could poison British politics.
