Former Prime Minister Margaret Thatcher deployed army of spies in Gibraltar after Falklands

Margaret Thatcher ordered that an army of spies be deployed across southern Spain to safeguard Gibraltar against a Falklands-style surprise attack.

The Prime Minister was obsessed with the possibility that the Spanish might attempt to retake the Rock, captured by Britain in 1704, while the Armed Forces were distracted by war in the South Atlantic.

The seizure by Argentina of the Falklands in April 1982 coincided with a thaw in Anglo-Spanish relations. Talks on the future of Gibraltar were to coincide with the opening of the border, closed by General Franco in 1969.

Presented with a Ministry of Defence assessment on the threat to Gibraltar three days after the fall of Port Stanley, Thatcher scribbled in the margin: “This is suspiciously like the Falkland Islands assessments before invasion.”

The MoD tried to calm the Prime Minister’s fears, explaining that post-fascist Spain was anxious to join both Nato and the EEC and would want to wreck these ambitions by emarking on a wild military adventure.

In any event, the isthmus joining Gibraltar to the mainland was easy to defend and reinforcements could be sent in a week, should a Spanish build-up be detected. But a caveat was inserted: “The territory could no doubt eventually be overwhelmed by vastly superior forces,” warned the planners.

Unconvinced, Thatcher ordered another assessment by the Joint Intelligence Committee, the coordinating body for Britain’s intelligence agencies. It was similarly comforting, suggesting that the only risk to the colony came from rogue elements in the Spanish armed forces staging a small-scale unauthorized assault as an “act of bravado”.

Quietly, measures were taken to beef up defences. An infantry company was sent to join the garrison battalion, together with Blowpipe anti-aircraft missiles. General Sir William Jackson, Gibraltar’s governor, wanted six Buccaneer bombers flown in to provide insurance against a Spanish amphibious exercise due to start on April 26.

But just two Jaguars were sent instead so as not to arouse suspicion. Thatcher’s worries continued after the war. In September 1982 the JIC admitted that there might be no warning at all of an attack by rogue units, prompting her to demand the deployment of a “large number of agents” to cover a “wide belt of territory” on the Spanish side of the border.

On October 28 her private secretary observed: “The Prime Minister has noted the precautions which we are taking to obtain early intelligence of possible Spanish action against Gibraltar but does not find the picture very reassuring. She would therefore welcome a further word with FCO (Foreign Office) and ‘C’ (The chief of the Secret Intelligence Service, MI6).”