Criticism has been levelled at a major Labour donor who likened Jeremy Corbyn’s advisors and supporters to Nazi Stormtroopers.

Michael Foster, who lives in Cornwall, spent thousands on legal fees last month in an unsuccessful challenge to the party’s decision to place Corbyn automatically on the upcoming leadership ballot.

Writing in the Mail on Sunday, Foster said: “This decision advantaged Corbyn and his Sturm Abteilung (stormtroopers).”

Foster, whose family has given £400,000 to Labour, added: “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.”

In the opinion piece, Foster said Shami Chakrabarti’s inquiry into anti-Semitism was “anything but independent” and accused shadow chancellor John McDonnell of “bullying,” before turning on Corbyn’s chief strategist Seamus Milne.

“Oppose them as a Jewish donor and the riposte from Seumas Milne, Corbyn’s mouthpiece, is that you are part of a Blairite, right-wing ‘conspiracy’ (the ancient racist rhetoric is that Jews don’t act alone, the malevolent Jew always conspires) to destabilise the democratically and legitimately elected leader.”

Foster came to national attention last year, in the immediate aftermath of Labour’s leadership battle, when he repeatedly shouted at Corbyn to “say the word Israel” during Corbyn’s address to Labour Friends of Israel.

His article in the Mail drew widespread condemnation from the Jewish community this week, including from Rhea Wolfson, a Labour National Executive Committee candidate, who called it “disgusting”.

She tweeted: “Chakrabarti had many clear messages, one important one was: no more Nazi analogies. Never appropriate, never acceptable.”

Similarly, Marie van der Zyl, vice-president of the Board of Deputies, said: “We have often made the point that Nazi and Holocaust comparisons are inflammatory and should be avoided in political discourse. The same is true in this case.”

However, she added that “many in the community are deeply concerned at some of the language and behaviour being exhibited by some Labour members,” saying the party still had “a very steep hill to climb”.