MINISTERS were urged tonight to rethink the region's involvement in the 'Son of Star Wars' missile defence project - after President Obama announced a surprise review.

A Commons debate heard that a window of opportunity had been opened up by the new president's signaling that he has not decided whether to press ahead with the scheme, or to abandon it.

The move from Washington has important implications for North Yorkshire, where two US bases will play a role in the multi-billion dollar project, designed to knock out nuclear warheads before they reach America.

RAF Fylingdales, south of Whitby, has already been upgraded with early-warning radar equipment which was switched on around 18 months ago.

Around the same time, Gordon Brown slipped out an announcement that the satellite ground station at Menwith Hill, near Harrogate, will monitor satellite warnings of potentially hostile missile launches.

Opponents have warned that Britain's involvement would make this country a potential target if a rogue state decided to attack the US with ballistic missiles.

Tonight's debate was led by Labour leftwinger Peter Kilfoyle, who argued that President Obama's recent statement had made it even more important that Britain's involvement was properly debated.

The MP said: "The programme is a very expensive way of destabilising the planet. Obama has been equivocal about missile defence but, in the light of what he has said, there are many questions that need to be asked."

Ed Davey, the Liberal Democrat foreign affairs spokesman, has also called for a rethink, saying recently: "President Obama's rightful scepticism about Bush's ballistic missile defence system gives the British Government a much needed way out - if it has the guts to take it."

But, in reply, defence minister Quentin Davies insisted MPs had already had several opportunities to discuss the missile defence project.

And he added: "The government has made a commitment that, if make a decision to locate interceptor missiles in this country - and no decision is in prospect - then there certainly would be an opportunity for parliament to debate before we do so."