Thatcher's Fight For Cold War Spy Revealed

Cold War documents released today show how Margaret Thatcher risked a diplomatic feud with Russia in an attempt to save the marriage of one of Britain's most important spies.

Oleg Gordievsky was a defector at the heart of the KGB who passed on significant secrets to MI6 and was credited with averting a potential nuclear confrontation, but he was forced to flee Russia after fearing his cover was blown in 1985.

In an operation approved by the prime minister he was whisked across the border to Finland by two MI6 agents in the boot of their car, but there was no time to extract his family.

Archived documents show that, once in the UK, the Russian defector sent Mrs Thatcher a personal message explaining how he accepted the decision to get him out alone, but added: "I must, however, go on hoping that some way can be found to secure the release of my family as, without them, my life has no meaning."

In an uncharacteristically soft tone she responded: "Having children of my own, I know the kind of thoughts and feelings which are going through your mind each and every day. But just as your concern is about them, so their concern will be for your safety and well-being.

"Please do not say that life has no meaning. There is always hope. And we shall do all we can to help you through these difficult days."

Behind the scenes Mrs Thatcher threatened Moscow that if the family was not released there would be a mass expulsion of KGB agents in London.

Mr Gordievsky's former boss at the KGB Mikhail Lyubimov told Sky News: "He would have been executed if he had been caught (defecting). And the KGB wanted to punish him somehow, so they wouldn't let his family leave."

The deal was refused and Mrs Thatcher proceeded to expel 25 suspected KGB agents - all of whom had been exposed by Oleg Gordievsky.

Two days later 25 UK nationals were ordered to leave Russia - including the two MI6 men who helped Mr Gordievsky escape.

It was feared the diplomatic spat would pull down the shutters on East West relations.

Documents show British Ambassador Sir Bryan Cartledge warned against further expulsions.

He cabled London: "Never engage in a p***ing match with a skunk: he possesses important natural advantages."

Britain did expel six more Soviets - and so six more Britons were forced to leave Moscow - but relations got no colder after that.

Mr Gordievsky's family were allowed to leave in 1991 but the marriage soon broke down and his wife and children returned to Moscow.