MI5 intercepted a letter from The Jewish Chronicle while spying on an Israeli politician, newly released files have shown.

JC chairman David Kessler wrote to Abba Eban, one of the state's founding fathers, on June 9, 1948, less than a month after Israel was created.

He commended Mr Eban, who lived in north London at the time, on speeches he made to the UN and discusses British reaction, noting optimistically: "There appears to be a far greater unity of thought on the Palestine question amongst the Jewish Community [sic] in England than there was previously."

However, reflecting the fact that Britain did not recognise Israel until May 1949, Mr Kessler says that the negative attitude of the Foreign Office "unfortunately is the guiding factor so far as the majority of the press is concerned, and also appears to dominate public opinion."

He speaks glowingly of The Manchester Guardian and the Tribune for taking an "anti-government line," but is less complimentary of The Times, which he says "for the most part continues a rather nauseating subservience to the FO".

The document is part of the 254-page dossier MI5 kept on Mr Eban between 1939 and 1948, as it intercepted letters and phone calls.

The National Archives also released documents which show that Mi5 spied on Robert Oppenheimer, the so-called 'father of the atom bomb', between 1945 and 1953.

Spymasters feared he may defect to the Soviet Union.