A historian at Cambridge University has uncovered the article written by Churchill in 1937, three years before he became prime minister.

Entitled 'How The Jews Can Combat Persecution' - by the Rt Hon Winston Churchill, it never saw the light of day after Churchill's private office stepped in to say publication would be "inadvisable".

The document lay buried in the university's Churchill archive for more than 60 years until historian Dr Richard Toye unearthed it while researching a new biography of the wartime leader. There is a suggestion the article was ghostwritten for Churchill.

But Toye said: "If it was ghostwritten, Churchill was apparently happy to put his name to this article in 1937. Like many of today's politicians, he was happy to endorse the sentiments contained in articles that were written for him."

Those sentiments include a complaint that cheap Jewish labour was "taking employment from English people" - a foreshadowing of today's arguments about the influx of immigrants to Britain.

The piece begins with reference to persecution of Jews over the centuries and refers to a new wave of anti-Semitism.

"It would be easy to ascribe it to the wickedness of the persecutors, but that does not fit all the facts," it reads.

"It exists even in lands, like Great Britain and the United States, where Jew and Gentile are equal in the eyes of the law, and where large numbers of Jews have found, not only asylum, but opportunity.

"These facts must be faced in any analysis of anti-Semitism. They should be pondered especially by the Jews themselves. For it may be that, unwittingly, they are inviting persecution - that they have been partly responsible for the antagonism from which they suffer."

The article goes on: "The central fact which dominates the relations of Jew and non-Jew is that the Jew is 'different'. He looks different. He thinks differently. He has a different tradition and background. He refuses to be absorbed."

Elsewhere, the article is sympathetic towards Jewish people and it is clear Churchill disapproves of their persecution.

He writes: "In fact, the Jew is as a rule a good citizen. He is sober, industrious, law-abiding. He identifies himself - up to a point - with the country in which he lives. He is ready, if need be, to fight and to die for it. Jewish soldiers served in the armies both of the Allies and of the Central Powers during the Great War. Twelve thousand of them died for Germany."

And Churchill ends by urging the British people to stand up for the Jews.

"The Jews are suffering from persecutions as cruel, as relentless and as vindictive as any in their long history," he writes.

"There is no virtue in a tame acquiescence in evil. To protest against cruelty and wrong, and to strive to end them, is the mark of a man. And when the victim of oppression is a brother in blood and faith, to attempt his succour becomes a sacred duty."

The document was originally offered to the US publication Liberty in 1937 but was withdrawn when another magazine for which Churchill wrote objected to him supplying a rival.

Churchill nevertheless tried to have it published in the Strand Magazine, but it declined the offer because it had already taken a similar article from former prime minister Lloyd George, according to Toye.

In early 1940, when Churchill was First Lord of the Admiralty, Sunday Dispatch editor Charles Eade was given leave to republish some of Churchill's old journalism. But when he asked to use this article, Churchill's secretary, Kathleen Hill, wrote to him on March 13 saying it would be "inadvisable".

Toye, a lecturer in British political and constitutional history, found the letter while researching his book Lloyd George And Churchill: Rivals For Greatness, to be published on March 16.

He said: "It appears to have been overlooked - I think a lot of people thought that the file it was in only contained copies of articles that had already been published.

"It was certainly quite a shock to read some of these things under Winston Churchill's name and it is obviously at odds with the traditional idea we have of him."