The rally, organised by the Campaign for Nuclear Disarmament (CND), took more than five hours to get through the city centre causing massive traffic disruption.

CND officials said they were delighted with the response and had never seen such a crowd.

The marchers, made up mainly of young people, created a festival atmosphere in Hyde Park as speakers took to the stage to address the crowd.

Tony Benn MP said it was time to stand up to Americans and close their UK missile bases.

"President Reagan cannot ignore us because President Reagan does not own Britain and Europe. This is our continent and we will shape it for ourselves" he said.

Labour Party leader Michael Foot added: "In this autumn of 1981 we stand at the most dangerous moment of all, ever since these nuclear weapons have come into operation and that is why it has been so necessary to re-establish this campaign."

He said that people now rejected the "insanity of nuclear weapons".