MILITARY strikes against Iran should not be ruled out, the Conservatives said last night as they criticised Tony Blair for failing to deal effectively with the looming nuclear threat.

Liam Fox, the Shadow Defence Secretary, used a speech to US Republicans to urge Mr Blair to follow the example set by President Bush and leave all options open on Iran.

Dr Fox was in Washington as part of a Conservative Party delegation to patch up relations with the White House after a falling out two years ago.

He told the right-wing Heritage Foundation that permitting a state in the Middle East to develop a nuclear weapon was a risk that should not be taken.

The diplomatic route must be pursued and Iran reported to the Security Council, but military action should also be kept as an option.

Dr Fox said: “Every pressure must be brought. But it was wrong for the European Union’s foreign affairs spokesman Xavier Solana to rule out the use of force. It is wrong for Britain’s Foreign Secretary, Jack Straw, to echo him.

“Frederick the Great once observed that diplomacy without arms was like music without instruments. We must keep all options open if we are to stand any chance of a diplomatic solution to the Iranian crisis.”

Dr Fox’s hawkish tone was in contrast to the repositioning of the Conservatives as a centre- ground party. But the Conservatives believe that Tony Blair, bruised by Iraq, has been too quick to rule out force in what could be a much more dangerous international situation.

The Shadow Defence Secretary also used his speech to challenge President Bush over plans to scale back a commitment to the Anglo-American Joint Strike Fighter (JSF) programme for a new generation of military jet aircraft.

He warned that the move could undermine British confidence in the “special relationship” with America.

“This particular programme is of great importance to Britain. We are relying on the JSF variant for use on our planned new aircraft carriers. But this variant may apparently be cancelled. Those two supercarriers will be central to our ability to project our power and to protect our interests. Large sacrifices have been made elsewhere in the defence budget to afford them,” he said.

If the project is scaled back, Dr Fox said that the ramifications would be profound. “Such an outcome would confirm in many people’s minds the mistaken idea that America cannot be relied upon to support us, even while calling upon our support to fight its wars.”

Dr Fox is in Washington with George Osborne, the Shadow Chancellor, and William Hague, the Shadow Foreign Secretary, who flew out to join them last night.

With David Cameron, the leader, on paternity leave for a fortnight, David Davis finally achieved his lifelong ambition to run the Conservative Party yesterday when he was made acting leader for 72 hours.

Mr Davis conducted yesterday morning’s strategy meeting while Mr Hague prepared for Prime Minister’s Questions, opening the session with a joke.

“I become leader at four o’clock and you’ll all be wearing ties by five,” he told Mr Cameron’s casually-dressed team. Mr Davis will remain as the acting leader until Mr Hague returns from the US on Saturday.

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