The head of the US missile defence project will visit the UK base which is key to its success, it was confirmed today.

Defence chiefs played down the significance of General Ronald Kadish's trip to RAF Fylingdales, an early warning radar station, in North Yorkshire.

But it comes just days after Defence Secretary Geoff Hoon signalled British participation in the controversial project.

Gen Kadish will tour the base on Wednesday after attending a conference on missile defence in London. ''It is an informal familiarisation visit,'' a Ministry of Defence spokeswoman said.

''It is not a pre-cursor to anything more serious.''

The general will not be accompanied by technicians, the spokeswoman said.

''He asked to visit the base and it would be churlish, if not difficult, to refuse,'' she added.

Labour MPs have spoken out against the U National Missile Defence programme.

Ministers insist they cannot even consider allowing the US to use the Fylingdales and Menwith Hill bases in North Yorkshire until a formal request is made.

However, Mr Hoon signalled British involvement in a speech he delivered just three days' ago.

The Defence Secretary warned of the growing threat of a missile attack on Britain from ''rogue state'' like Iraq. And he said the development of a defence against ballistic missile attack was ''in the interests of the UK and its people, just as much as it is in the interests of the United States''.

Mr Hoon last month told MPs he had ordered a detailed analysis of the implications of missile defence.

However, on Tuesday he again insisted the US had not yet decided whether they needed to use the British bases for their so-called ''Son of Star Wars'' system.