by Richard Norton-Taylor

Aldermaston, England - More than 30 people were arrested yesterday during one of the biggest anti-nuclear protests at the Atomic Weapons Establishment at Aldermaston for 10 years. The gates of the site were blocked as people attached themselves to concrete blocks which had to be broken apart by police. Others climbed scaffolding or lay in the road at the demonstration by about 400 people to mark the start of the UN World Disarmament Week.

They were protesting against a decision to modernise the Aldermaston plant in Berkshire and plans to develop a new warhead for nuclear missiles that the government wants to buy to replace the Trident system.

The government plans to spend nearly £6bn on Aldermaston over the next three years. Ministers claim the money is needed to preserve Britain's ability to manufacture nuclear warheads safely; they say a decision has not yet been taken to develop new, "more usable" warheads with the help of American knowhow.

The Guardian revealed earlier this year that one of the MoD's senior officials told a private meeting of arms companies that a decision to replace the existing stockpile of nuclear warheads had already been taken despite ministers repeatedly denying there were any plans to replace them and insisting that no decision would be taken until the next parliament, probably sometime after 2010.

Daniel Viesnik, spokesman for Trident Ploughshare, said: "The government does not seem to take notice of anything else other than direct action. We are opposed to the development of a new generation of warheads and protesters feel more extreme measures like [yesterday's] have to be used to get attention."

Kate Hudson, chair of CND, said the protest showed there was a strong increase in public support for nuclear disarmament.