British police were tonight forced to lock the doors to the parliament after protesters attempted to force their way into the Palace of Westminster.
Scotland Yard said none of the environmental demonstrators, campaigning against airport expansion, had managed to breach security.
There was one confirmed arrest, a 23-year-old woman for breach of bail.
A spokesman said an "appropriate policing plan" had been put in place to deal with the protest, which had been expected.
PA
