More than half of British voters believe that Jeremy Corbyn’s inability to tackle Labour’s antisemitism crisis demonstrates that he is not fit to be Prime Minister, according to a new poll.

The poll, conducted by ComRes for the Jewish News, shows that that number includes almost a third of Labour people who voted Labour in 2017 – as well as 15 per cent of people who, despite believing Mr Corbyn is unfit for office, still plan to vote Labour.

It also shows a large increase in those who believe Labour has significant issues with antisemitism. Nine months ago, a third of the general public responded affirmatively when asked about the issue; that number is now over half, at 51 percent.

There is also the suggestion that even within Labour there is a growing realisation of the party’s problem.

Last summer, just 16 percent of Labour members said they believed the party had a serious issue with antisemitism. That number has almost doubled, to 29 percent.

However, at the same time the poll suggests a hardening of attitudes among Labour backers. Just 12 percent of those intending to vote Labour were willing to dismiss the idea that Jeremy Corbyn “is the target of a concerted smear campaign” by political opponents attempting to discredit him over antisemitism.

Andrew Hawkins, chair of ComRes, told the Jewish News that “being soft on racism must account for a major part of Labour’s malaise given that almost one in three of the party’s own voters at the last election believe its leader is not fit to be Prime Minister because of the issue.”

Another ComRes national poll released on Wednesday night showed a collapse in those intending to vote for the Conservatives, with the Tories dropping from 32 percent to 23 percent.

However, the slump barely had an impact on Labour’s vote share, with most appearing to have gone to Nigel Farage’s new Brexit party.