Nato believes that Serb generals are close to signing an agreement following the resumption of negotiations with the alliance's military chiefs.

The talks reconvened on Tuedsay evening after G8 ministers and Russia agreed a resolution to put before the United Nations on the Serb retreat from Kosovo.

Tony Blair: Yugoslavs have no excuse to drag their feet again

The BBC understands that crack British paratroopers and gurkhas could enter Kosovo within 12 hours of the Serb generals accepting the withdrawal terms.

Their task would be to secure a 12km stretch of road from the Macedonian border to Pristina. Mines and other booby traps may have to be cleared to create a safe route for the returning refugees and the international force that would accompany them home.

Bombing continues

The G8 agreement is based on the document drawn up by the EU envoy to the Balkans, Martii Ahtisaari, and the Russian envoy, Viktor Chernomyrdin, last week.

The resolution will not be formally adopted until Nato ends its bombing campaign.

Tony Blair: "The text is strong and clear and meets our requirements"

Mr Blair said Nato's bombing would be suspended if the Serbs kept the agreement.

But the prime minister warned MPs not to "take Milosevic's assurances on trust".

He said the Nato bombing of Yugoslavia would continue until the alliance could be sure the Serbs were pulling out of Kosovo.

If the agreement, which the prime minister said would be legally binding, is backed by the UN it will authorise international troops to use force to ensure the agreement's implementation.

The terms of the agreement allow for the withdrawal of all Serbian military and paramilitary forces from Kosovo.

It also promises the safe return of the Kosovan Albanian refugees, under the protection of an international peacekeeping force, in which Nato would play a key role.

The agreement, Mr Blair said, gives "the Yugoslav authorities no excuse to drag their feet again".

"Providing the Serbs, at long last, honour their undertakings and begin a verifiable withdrawal of their forces the Nato bombing can be suspended, the security council resolution passed and the international force can deploy into Kosovo by the end of this week."

He added it was time to start planning for the reconstruction of the Balkans, of which Serbia was a part.

But he added that Serbia would be refused European Union aid while Slobodan Milosevic remained the country's president.

"Until Milosevic goes Serbia cannot take its true place in the family of world nations."