DEFENCE Secretary Geoff Hoon has confirmed that the Government wants to upgrade RAF Fylingdales' missile defence capability - in advance of a US "Son of Star Wars" programme.

In a discussion paper published last night, the minister steamrollered over peace objectors' concerns, and said the North York Moors site might need to be improved.

This is despite an admission by the Ministry of Defence last week in a Commons answer that there is no immediate threat to the UK.

There would be no "significant change" to the outward appearance of the radar at Fylingdales, with the main changes being to computers and their software.

Mr Hoon said: "The US has not yet put any formal request to us for use of UK facilities. The Government would agree to such a request only if it were satisfied that the overall security of the UK and the Alliance would ultimately be itself enhanced."

The discussion paper says: "There are an increasing number of threats to the security of the UK and her allies."

It adds: "Potential threats are growing and cannot be ignored. If we are to meet these prospective threats, we need to plan ahead and prepare properly."

The paper warns that the UK and the West's population centres could be targets of missiles by terrorists. But it argues that RAF Fylingdales is not a plausible target.

"It could nonetheless be a key building block for any future system of active missile defence protection for the UK and Europe."

The paper points out the vital role that Fylingdales provides - and could provide - to the defence of the UK and the US.

"Early warning radars would need to be upgraded in order to provide a missile defence capability, so that incoming threat objects could be tracked more accurately.

''Resulting data could be fed back to the UK's Missile Warning Cell, and to the US Ground-Based Mid-Course Defence control centre.''

The additional warning time provided by RAF Fylingdales against a threat from the Middle-East "is very substantial", says the paper.

In the Commons yesterday, York Labour MP Hugh Bayley was given an assurance from Mr Hoon that the discussion document would be "widely circulated for a thorough and careful consideration of the arguments for and against."

Liberal Democratic spokesman Paul Keetch said: "The UK cannot participate in any missile defence scheme, or allow facilities to be used on UK soil, unless it enhances the security of the UK, and enhances the security of all of the alliance."