'We will neither flinch nor falter'

Tony Blair, faced with evidence of fraying public support at home and wobbles in the alliance against terrorism, today delivered his strongest declaration yet that he would neither "flinch nor falter".

The Prime Minister, speaking to the Welsh Assembly in Cardiff, embarked on a deliberate and sustained effort to emphasise the difficulty of the campaign - and the high risk involved. "Every part of this is difficult," he warned. "Every part requires courage, conviction, hard work. In every part, there may be setbacks from time to time."

At the same time, however, he set out to lay down the iron logic which meant the US, Britain and the other alliance members must act.

On 11 September, thousands were killed in cold blood in the worst terrorist attacks the world has ever seen. "That is a fact."

Those responsible were the al Qaeda reared by Bin Laden. That, said Mr Blair, was a fact barely disputed by anyone any more - and the initial "significant" intelligence evidence "is now a flood, confirming guilt".

Bin Laden and his network said they considered it "their duty" to commit more terrorist acts. The Taliban, given an ultimatum to deliver up Bin Laden, had refused. "These are also facts."

Those facts, taken together, Mr Blair went on, led to one inescapable conclusion: "If we do not act, al Qaeda will have perpetrated this atrocity, the Taliban will have sheltered them, and we will have done nothing.

"We will have done nothing despite the fact, also inescapable, that they intend to commit more atrocities unless we yield to their demands - which includes the eradication of Israel, the killing of all Jews and the setting up of fundamentalist states in all parts of the Arab and Muslim world."

At the same time Mr Blair struck a note of caution. "This is not a conventional conflict,î he stressed. "It is not a battle for territory per se or for the subjugation of Afghanistan."

The Prime Minister set out his central theme: "We have a group of people in Afghanistan who are the sworn enemies of everything the civilised world stands for, who have killed once on a vast scale and will kill again unless stopped.

"They can't be negotiated with. They refuse to yield to justice. And they have one hope: that we are decadent, that we lack the moral fibre or will or courage to take them on."

He added: "We won't falter. We will not stop until our mission is completed. We will not flinch from doing what is necessary to complete it."

Mr Blair also took on the charges that the air campaign was doing unwarrantable damage to innocent civilians' lives and property.

The Taliban regime itself - "cruel, dictatorial and oppressive" - had forced four and a half million refugees to flee even before 11 September. And he appealed for the

Taliban's claims of civilian casualties to be treated with deepest scepticism.

The Prime Minister said: "Never forget how we felt watching the planes fly into the trade towers. Never forget those answerphone messages, never forget how we felt imagining how mothers told children they were about to die. Never forget the guts of the firefighters and police who died trying to save others, never forget the gloating menace of Osama bin Laden in his propaganda videos."

The Prime Minister later today sets out on the latest stage of his diplomatic mission-to shore up the Alliance. No10 would not confirm his destination but it was clear that he would focus on two key objectives: to maintain support for the alliance, particularly in the Arab world; and to try, somehow, to breathe life back into the Arab-Israel peace process.

Mr Blair's speech was the clearest signal yet of the acute concern in Downing Street that the campaign could sour. It was well trailed in advance and designed to stiffen resolve in the wake of an ICM poll in The Guardian today, which found public support for military action down by 12 points in the past fortnight, from 74 to 62 per cent.

The poll still showed strong backing for the use of British troops on the ground in Afghanistan, with 57 per cent for their use and only 29 per cent against.

More worryingly for Mr Blair, 54 per cent of those questioned would back a pause in the bombing campaign to allow aid convoys to reach the needy in Afghanistan. Only 29 per cent said they would disagree with a pause.