A prominent Labour donor has been suspended by the party after outspoken attacks on leader Jeremy Corbyn.

Michael Foster was barred after writing a newspaper article in which he claimed to have been smeared as a Jewish donor to the party and compared Mr Corbyn’s allies to Hitler’s stormtroopers.

The suspension means that Mr Foster will not be able to take part in the leadership contest between Mr Corbyn and challenger Owen Smith.

Mr Foster wrote a highly critical column in the Mail on Sunday after the High Court ruled against his attempt to stop Labour from allowing Mr Corbyn to automatically stand for re-election as leader.

In the article on August 14 he highlighted a “divisive, aggressive holier-than-thou cadre of hard-Left socialists” supporting Mr Corbyn through the Momentum movement.

“In the midst of this, something is rotten. You are either with them, or you are labelled as being against them and so excluded, briefed against, often threatened and intimidated.

“If you are like me, a Jewish donor to Labour, you are smeared as a Blairite conspirator, plotting to falsely use the accusation of anti-Semitism to damage the Left.”

He added that the High Court decision had “advantaged Corbyn and his Sturm Abteilung (stormtroopers)”. The SA, also known as the Brownshirts, were the paramilitary wing of the Nazi Party.

Mr Foster was informed of his suspension in a letter from party general secretary Iain McNicol last week.

“The rule of law is being ignored because of intimidation by Corbyn, backed by Momentum, his Praetorian Guard,” Mr Foster said.

“This will presage the purge of opponents within the Labour Party and then the deselection of any MP who is not signed up to the Left’s ideology.

“Criticise Corbyn by using the free press and within hours 11,000 people petition the National Executive Committee for your suspension. The coward NEC then takes away your democratic right both to free speech and to vote and you are excluded from the Party. There is no due process.”

He added: “Corbyn is not just bad for Labour, he is bad for Britain’s democracy.”

He is accused of breaching a party leadership rule that “all eligible members and supporters must conduct themselves in a calm and polite manner and be respectful to each other at all times”.

Mr McNicol said in a letter to Mr Foster: “It is important that these allegations are investigated and the NEC will be asked to authorise a full report to be drawn up with recommendations for disciplinary action if appropriate.”

The suspension had been publicly called for by shadow chancellor John McDonnell, Mr Corbyn’s most senior ally.

He had claimed that supporters of Mr Corbyn had been suspended in a “rigged purge” by the party machine but “no action has been taken against Michael Foster, the Labour party member who abused Jeremy Corbyn’s supporters and staff as Nazi stormtroopers”.