How UK nuclear defence relied on four pennies

LIKE something out of Monty Python, Britain’s nuclear deterrent in the Sixties relied on a ‘bizarre’ arrangement involving an AA radio link, a telephone box... and a reverse-charge phone call from the prime minister.

Historian Peter Hennessy said that if it ‘had been relayed to the KGB chief, he would have regarded it as a complete plant and a spoof’.

According to details of the method revealed in documents kept at the National Archives in Kew, the plan was developed after Lord Mountbatten, then chief of the defence staff, pondered what to do in the event of a four-minute warning if Harold Macmillan was away from his desk.

The file dates back to 1961-62 and detailed Lord Mountbatten’s Cold War concerns.

Mr Hennessy told the Cheltenham Literature Festival: ‘The real worry in the face of this increased Soviet menace was that the prime minister might be out of town in his Rolls-Royce, and what they would do, as he would have to authorise the retaliation.

‘The Treasury didn’t want to spend any money, Macmillan didn’t want to have any fuss at all. The answer was to use the Automobile Association.’

Whitehall arranged for the premier’s car to be fitted with a radio link used by the AA to call their mechanics, which would tell the driver that he had to find a phone box so Macmillan could call Whitehall.

It was suggested that government drivers carried four pennies as that was the minimum sum needed in a GPO phone box. But Sir Timothy Bligh, Macmillan’s principal private secretary, came up with a plan for occasions when the driver had no change.

He wrote: ‘It is a simple matter to have the cost of any telephone call transferred by... requesting reversal of the charge.’

The AA link was installed just in time for the 1963 Cuban missile crisis, and remained until early 1970. Mr Hennessy said the arrangement ‘was so English and so bizarre that had it appeared in an Ealing Comedy it would have not been believed’.