The assertion of Tom Watson, Labour's deputy leader, that Trotskyists were attempting to join his party, has been a refrain voiced for the best part of a century.
The total failure of far-left groups such as the Communist Party to appeal to the British working class meant that entryism into the Labour Party was the only option.
Trotskyism has always interested Jews because of its almost Talmudic adherence to text and interpretation. Its leaders were treated like Chasidic rebbes, held court for their followers and did not work for a living.
Despite Trotsky's comment that he was not a Jew, but an internationalist, Stalin used antisemitism in his struggle against Trotsky in the mid-1920s.
In exile Trotsky attracted a disproportionate number of Jews to his standard. Tony Cliff - aka Yigael Gluckstein from Zikhron Ya'akov - founded the Socialist Workers Party in the UK, while Ted Grant - aka Isaac Blank from Johannesburg - was the mentor of the Militant Tendency.
Trotskyist leaders were treated like Chasidic rebbes
Both groups embedded themselves in the Labour Party in the 1960s .
Grant - whose family ran a grocery store in Johannesburg - and his sister Zena joined other members of the Litvak community in forming the Bolshevik-Leninist League in 1934.
His father had come from Tavrig, near the Lithuanian-Prussian border. The entire family left behind in Tavrig perished in the Shoah.
Cliff came from the Zionist elite in the Yishuv and gradually moved to a Trotskyist position. He was a leading light of Brit Spartakus, a group which campaigned against attempts to enlist Hebrew University students into the British forces to fight Nazism.
In South Africa, some young Jews, shocked at institutionalised apartheid, found their salvation in Trotskyism.
In the UK, Blank joined the Labour League of Youth while his fellow Jewish South African, Max Basch - aka Sid Frost - joined the Independent Labour Party. They had both been influenced by Frank Glass, a founder of the South African Communist party who ran the left-wing Vanguard bookshop in Johannesburg. Converting to Trotskyism, Glass left for China in 1931 to continue his life as a revolutionary activist where he was known as Li Fu-jen.
Some left-wing Zionists, members of Hashomer Hatzair, such as the Belgian theorist Abram Leon, left Zionism as a reaction to Hashomer's blind subservience to Stalin and in disgust at the Moscow show trials of the 1930s .
Despite their Jewish origin, both Cliff and Grant regarded the Second World War as a contest between rival imperialisms - that one side was as bad as the other when it came to the interests of the working class.
It is interesting to note that both the Corbynistas and the Communist Party of Britain (CPB) have ridiculed Watson, but simultaneously opposed entryism.
Jeremy Corbyn has long written a column for the CPB's Morning Star newspaper while his communications director, Seumas Milne, started off his political career in Straight Left, the organ of communist orthodoxy, opposed to the more open eurocommunism, and decidedly sympathetic to the Soviet Union.
Is all this then a replay of old battles, between Trotskyists and their pro-Kremlin opponents, stretching back to the 1920s?
While the Corbynistas have never acted as mediators in bringing Israelis and Palestinians together, but only as propagandists for one side, both Militant and the Alliance for Workers' Liberty, mentioned by Watson, have actually pursued a much more balanced approach. While by no means pro-Israel in the conventional sense, there is at least an attempt to understand the fears of the Jews of Israel and the reality of the conflict.
The Jewish Bolshevik, Karl Radek, joked almost 100 years ago: "What's the difference between Moses and Stalin? Moses took the Jews out of Egypt, Stalin takes them out of the Communist Party."
Will the same be said of Mr Corbyn and Labour in the years to come?