Margaret Thatcher refused 5 times to clear Victor Rothschild Accused of Working as Soviet Spy

Nathaniel Mayer Victor Rothschild, 3rd Baron Rothschild, Bt, GBE, GM, FRS (31 October 1910 – 20 March 1990), was a senior executive with Royal Dutch Shell and N M Rothschild & Sons, an advisor to the Edward Heath and Margaret Thatcher governments of the UK, as well as a member of the prominent Rothschild family.
Rothschild was recruited to work for MI5 during World War II in roles including bomb disposal, disinformation and espionage, winning the George Medal for "dangerous work in hazardous circumstances".
He appears several times in the book Spycatcher, which he hoped would clear the air over suspicions about his wartime role and the possibility he was involved in the Cambridge spy ring. He was still able to enter the premises of MI5 as a former employee and was aware of suspicions there was a "mole" in MI5, but felt himself above suspicion. While Edward Heath was Prime Minister, Rothschild was a frequent visitor to Chequers, the Prime Minister's country residence. Throughout his life, he was a valued adviser on intelligence and science to both Conservative and Labour Governments. In 1993, after the dissolution of the Soviet Union, six retired KGB colonels, including Yuri Modin, the spy ring's handler, alleged Rothschild was the "Fifth Man". Modin claimed, "Rothschild was the key to most of the Cambridge ring's penetration of British intelligence. 'He had the contacts,' Modin noted. 'He was able to introduce Burgess, Blunt and others to important figures in Intelligence such as Stewart Menzies, Dick White and Robert Vansittart in the Foreign Office...who controlled MI6." Christopher Andrew and Vasili Mitrokhin, in The Mitrokhin Archives, make no mention of Rothschild as a Soviet agent and instead identify John Cairncross as the Fifth Man.

Lord Rothschild Accused of Working as Soviet Spy