An anti-nuclear protestor briefly interrupted an address by British Prime Minister Gordon Brown today, storming up onto a stage where he was speaking in central London.

Carrying a placard saying "Nukiller Power No", the man was bundled off the stage by security staff at Methodist Central Hall, where Brown spoke along with his Conservative and Liberal Democrat rivals for elections this week.

"I'm used to worse," joked Brown, after organisers of the gathering of non-governmental organisations (NGOs) apologised for the disturbance. "You may have been in the House of Commons sometimes," he added.

The incident came with only three days to go until Thursday's general election in which Brown is struggling to cling on to power despite polls showing opposition Conservatives in the lead in knife-edge ballots.

Brown spoke at the meeting after addresses by Conservative leader David Cameron and Liberal Democrat leader Nick Clegg, whose party has leapfrogged Labour into second place in opinion polls during the month-long campaign.