A Jewish Labour donor and former party candidate is preparing later today to legally challenge the party’s decision to automatically place Jeremy Corbyn on the leadership ballot.

Michael Foster, who stood for the party in a Cornish constituency at last year’s general election, has donated more than £400,000 to Labour since 2010.

Speaking on the BBC’s Today programme, Mr Foster said: “There were three bits of legal advice from different QCs, all of which were contrarian, and none of the people in the room were unbiased in their view of that advice.

“All I am simply saying is, the advice that was taken was certainly not given the expert consideration that it would receive from a High Court judge.”

Commenting on the time frame for his challenge to the National Executive Committee’s decision, Mr Foster said: “If the case is heard – and I think it will be heard – the matter will be adjudicated in days not weeks.”

Tom Watson, Labour’s deputy leader, said Mr Foster’s challenge was “very unhelpful and destabilising to the Labour Party”.

Last October Mr Foster heckled Mr Corbyn at the end of his address at a Labour Friends of Israel session at the party conference.

Mr Foster, angry that the Labour Leader and long-term pro-Palestinian campaigner had not mentioned Israel by name during his speech, shouted “say the word Israel! Say the word Israel!” at Mr Corbyn.

In a piece he wrote for the Daily Mail earlier this year, Mr Foster sharply criticised Mr Corbyn’s “crass, hateful and ignorant support” for those within Labour who “blend Israel and Zionism into the supposed demagoguery of the classic Jew, an all-controlling malevolent demon”.