Britain's key atomic weapons plant could be at the centre of a multi-million pound nuclear arms expansion programme, it is reported.

Such an extension at the Aldermaston site, in Berkshire, would allow Britain to test, design and build a new generation of smaller nuclear weapons.

These could be used against terrorist groups and rogue states, according to The Observer newspaper.

The Ministry of Defence denied plans to develop new nuclear weapons, but said it would retain the capacity to do so as a prudent precaution.

Liberal Democrat foreign affairs spokesman Menzies Campbell said Labour must not take a unilateral decision about replacing the existing Polaris weapons.

He said: "Parliament must be given a full-scale role in the discussions leading up to it."

Sophisticated plant

Proposals to be submitted to West Berkshire planning authorities outline one of the most state-of-the-art weapon plants in Europe, the newspaper reports.

Rendel: Government must clear outline its plans

It claims the plans would see the Atomic Weapons Establishment (AWE) close the nearby 270-acre Burghfield site, which is where Britain's atomic warheads have been produced for nearly 50 years.

This would be replaced with a complex capable of designing new atomic weapons.

Mr Campbell said: "Whether or not to replace Trident will be one of the most significant political decisions of the next 20 years."

He called for consensus between the political parties to be reached and he added: "We cannot have any repeat of the precedent set by Labour in the 1970s when Polaris was updated without the Cabinet being fully informed."

'No indication'

Liberal Democrat MP for Newbury David Rendel, which includes Aldermaston, said the government should be more forthcoming about its intentions.

At present there is no indication that anything other than research into nuclear weapons will be taking place

David Rendel MP

"We knew that the facilities at Burghfield would be moved to Aldermaston, and that Aldermaston would be involved with further research, since the current contract came into operation," said Mr Rendel.

"At present there is no indication that anything other than research into nuclear weapons will be taking place at Aldermaston."

But he added: "The best way to calm fears about nuclear weapons at Aldermaston is if the government comes clean about its future nuclear policy."

'Early stages

An MoD spokeswoman said there were currently no plans to develop or build new nuclear weapons.

She said there was a proposal to concentrate all Trident activity, such as simulated testing and some maintenance functions, at Aldermaston.

This, she said, might require expanded premises.

But that involved a long process and was at the "very early stages of genesis."

There are no plan to construct new facilities for the purpose of building new nuclear weapons, she emphasised.

But according to the newspaper the MoD is submitting the planning application - which is subject to normal planning procedures - on behalf of AWE.

Anti-terrorist checks

The proposals must abide by normal planning procedures.

This is because crown immunity was removed after AWE, effectively private contractors, took control of the running of Aldermaston in 1993.

The news comes as the government's nuclear security chief, Michael Buckland-Smith, said staff shortages had forced a cut back on anti-terrorist checks at nuclear facilities across the UK.

The director of the Office of Civil Nuclear Security admitted in his office's annual report that the agency is having trouble recruiting staff, Scotland on Sunday reports.