IT was the moment the partnership between Margaret Thatcher and Ronald Reagan almost hit the rocks.

The US invasion of the Caribbean island of Grenada in 1983 came as a bitter shock to the Prime Minister, who was appalled at the American military intervention in a Commonwealth state.

Papers now released show how the President gave her virtually no time to object before committing US forces.

The crisis erupted when a group of what Reagan referred to as "leftist thugs" assassinated the elected prime minister and seized control of the island.

On October 24, Downing Street received a cable from Mr Reagan saying he was giving "serious consideration" intervening.

Mrs Thatcher fired off her own telegram expressing her "gravest concern" but Mr Reagan decided to proceed.

Mrs Thatcher's humiliation was compounded as only the day before Sir Geoffrey Howe had told the Commons the Government had no reason to think US intervention was likely.