He said the Allies had adopted the right position, and that the campaign against Serbia would continue for as long as necessary.

Mr Blair spoke to the BBC soon after Nato agreed to send 8,000 troops to Albania to help with the mounting refugee crisis. He said that problem was now being dealt with, and he praised British troops there for doing "the most extraordinary job".

He said: "We believe the air campaign will be successful. We have now been doing immense damage to his whole military infrastructure, to his military capability, to his lines of communication, to his supplies, to his killing machine on the ground.

Tony Blair: "Real damage is being done"

"I can say that today's attacks on his military police and his paramilitaries on the ground in Kosovo were actually very successful.

"It won't be done overnight. There's no point in trying to pretend it will be, but we are doing immense damage to his war machine."

No ground troops

Though Mr Blair refused to commit Nato forces to a ground invasion of Kosovo, he did say troops would form part of an international protection force to allow the ethnic Albanians to return to their homes.

He said: "Nato does not have proposals for a land force to invade Kosovo. We do have proposals, however, to make sure we have the requisite troops in the area to form a protection force to let people back into Kosovo."

Yugoslavia's claim that it had stopped its violence in Kosovo were rejected by Mr Blair.

On whether Yugoslav President Slobodan Miolsevic was a war criminal, he said it was not for one country to decide.

"But he needs to know that the process of ethnic cleansing and probably a whole series of atrocities that we don't yet know the full picture of, will be brought home to him in the end," he said.

Labour dissent

Labour left-winger Tam Dalyell angrily rejected the prime minister's comment that no-one now questioned the attacks.

Mr Dalyell, who will be among Labour MPs speaking at a London rally on Sunday staged by the Committee for Peace in the Balkans, said: "He said no-one's asking questions about whether it is necessary to continue bombing.

"I may be a nobody but along with those on the Committee for Peace in the Balkans, we certainly are asking questions. Is the policy to bomb Yugoslavia back to the Middle Ages?"

He added: "Repeatedly, during this interview, Blair was muddle-headed beyond belief. For example, when he was asked whether we should deal with President Milosevic as a war criminal or whether he was someone with whom we will have to stake out a deal, he had no answer."

Meanwhile, the Nato campaign has, according to an opinion poll, consolidated Mr Blair's standing as one of the UK's most respected leaders since World War II.