The isolated islands lie off the South American mainland

Shadow defence secretary Liam Fox gave the warning after newspaper reports that the Argentinean air force had doubled in size.

Argentina's ambassador to London has written to the newspapers to say there has been no such dramatic increase.

And Mike Summers, from the Falklands Island Council, said the possibility of an invasion was "almost laughable".

Britain claimed sovereignty of the Falklands in 1833 but it has remained disputed , with Argentina invading in 1982.

'Clear signal'

Dr Fox questioned whether defence cuts meant the UK could raise the kind of task force it used in Falklands War.

He said there had been a war of words in recent times, with Argentina forging an alliance with Venezuela's President Hugo Chavez, who has called for the UK to hand over the islands.

He was worried the UK Government was sending mixed signals while there were "increasingly bellicose noises" coming out of Buenos Aires.

"We must make sure that we make it clear to Argentina that we would do absolutely anything to defend the Falklands and any action from them would be extremely foolish."

Buenos Aires denies the claims and the Ministry of Defence says Argentina is a valuable ally.

British officials say Argentina had 300 planes at the time of the 1982 Falklands invasion and now has just 100.

Mr Summers said: "I don't think we are overly concerned at the moment about what's happening in Argentina. The possibilities of them mounting an invasion are so remote as to be almost laughable."