Prominent Brexit supporter Jacob Rees-Mogg on Wednesday said that British Prime Minister Theresa May's new plan for Brexit was worse than her old proposal, as the embattled PM seeks a fourth attempt to pass a Brexit deal.

Rees-Mogg, an influential backbencher in May's Conservative party, said that May could lose a parliamentary vote on her new proposal by more than the record defeat she suffered at her first attempt to pass her Brexit deal.

"It is worse than it was last time," Rees-Mogg told ITV's Peston programme. "If she were to put the bill in the form she's proposed ... she would lose by more than 230. I think the mood has turned very sharply against it."