EXCL Labour by-election candidate Christian Wolmar called on Jeremy Corbyn to quit
Labour's by-election candidate in next month's crunch Richmond Park by-election told Jeremy Corbyn his "time was up" in the summer, PoliticsHome has learned.
Christian Wolmar said Mr Corbyn should do the "honourable" thing and make way for another leader.
His outspoken attacks, on his Twitter page, came despite the fact he had backed Mr Corbyn's original leadership bid in 2015.
The first tweet was posted on 28 June as the Labour leader was engulfed in a major crisis as shadow ministers resigned in the wake of the EU referendum result.
A second tweet, published two days later, has since been deleted. It said: "Every hour that @jeremycorbyn does not resign, means another hour of lost opportunity to attack the Tories. He must show he is honourable."
Transport expert Mr Wolmar went even further in his criticism of Mr Corbyn during the Labour leadership contest in August.
He said: “I have had many conversations with people who worked with him and in everything you can see that he’s just not a sort of person who leads.
“He seems to think that decisions are made by osmosis and that he can sit their like a bystander, not realising that he’s the leader and has to be effective.”
Mr Wolmar was confirmed as Labour's candidate in Richmond Park yesterday. Significantly, the press release making the announcement did not include a comment from Mr Corbyn.
The by-election, which will be held on 1 December, has been called after sitting Tory MP Zac Goldsmith quit over the Government's backing for a third runway at Heathrow.
Some senior Labour figures had urged the party not to stand a candidate, and to urge their supporters to vote Lib Dem instead. The Greens have said they will not put forward a candidate.
Accepting the Labour nomination, Mr Wolmar said: "The Liberal Democrats and Zac Goldsmith supported every terrible decision taken by the last coalition government, from austerity to the unnecessary and expensive top-down reorganisation & creeping privatisation of the NHS. The Lib Dems are not a progressive alternative, but Labour is.
"Zac Goldsmith played a key role in the Leave campaign which led to the decision to take us out of the EU – a decision that 72 per cent of voters here opposed. The only way to send a message to this government and that we do not accept what they are doing to our country is to vote Labour.”