Downing Street has rejected suggestions by more that 50 former diplomats that the UK's Middle East policy is "doomed" to failure.

Number 10 welcomed the opportunity for debate but rejected suggestions that support for the Bush administration was leading to instability in the region.

"Our goal is clear and that goal is stability and democracy," the prime minister's official spokesman said.

"The important thing is...whether you believe the spread of democracy in the Middle East will end the breeding ground of terrorism."

He added that if the diplomats were suggesting Iraq was better off under Saddam Hussein "then our view is that we disagree".

Direction

In an open letter to the prime minister, the foreign policy experts called on the government not to back US policies on the Israeli/Palestinian conflict.

They expressed "dismay" at the latest plans to recognise some Jewish settlements in the West Bank.

There was also criticism of the handling of post-war Iraq.

"The conduct of the war in Iraq has made it clear that there was no effective plan for the post-Saddam settlement," the letter said.

"All those with experience of the area predicted that the occupation of Iraq by the coalition forces would meet serious and stubborn resistance, as has proved to be the case.

"To describe the resistance as led by terrorists, fanatics and foreigners is neither convincing nor helpful."

The signatories said the time had come "to make our anxieties public, in the hope that they will be addressed in parliament and will lead to a fundamental reassessment".

But Number 10 rejected suggestions it was pursuing the wrong policies, saying that Iraqi freedom was "only possible because Saddam has been removed".

The prime minister's spokesman said it would wrong to personalise the argument, but added that the "private citizens" were "perfectly entitled to any views that they wish".

Experts

The former diplomats, some of whom served in the Middle East, accepted that the UK should work with America, but warned against counterproductive policies.

"We share your view that the British government has an interest in working as closely as possible with the United States on both these related issues, and in exerting real influence as a loyal ally," the letter said.

"We believe that the need for such influence is now a matter of the highest urgency.

"If that is unacceptable or unwelcome there is no case for supporting policies which are doomed to failure."

Reacting to the letter, Liberal Democrat foreign affairs spokesman Sir Menzies Campbell said it had been signed by "a group of people who are almost certainly the most expert in Britain on the issue".

"The prime minister would be well advised to take account of their criticisms," he added.

"When the House of Commons was persuaded to endorse military action against Iraq it was among other things on the footing that the road map would be implemented, and that the two state solution would have priority.

"Britain's efforts to explain away Ariel Sharon's unilateral action as a first step ring false and have no doubt prompted this response."