Tony Blair wants a draft UN resolution to halt fighting in the Middle East to be adopted as quickly as possible, it was claimed yesterday.
The wording of the text was finally agreed by the US and France after intense negotiations on Saturday night.
It calls for a "full cessation" of hostilities between Israel and guerillas of the militant Hezbollah group in Lebanon, but allows Israel the right to defend itself if attacked.
The wording is a victory for the US and Israel, which had resisted demands from France and other nations for an unconditional halt to the fighting - something the Israelis believed would leave them vulnerable to Hezbollah rocket attacks.
The resolution must now go before the full 15-nation UN Security Council and gain Israeli and Lebanese acceptance.
Diplomats said the document was likely to be adopted this week.
Yesterday, Mr Blair hailed the agreement as "an absolutely vital first step in bringing this tragic crisis to an end".
The priority now was to get the resolution adopted as quickly as possible, he added.
Speaking at 10 Downing Street, Mr Blair said: "It should mean that, on the adoption of the resolution by the full Security Council, there is then a full cessation of hostilities at that point on both sides.
"What is then necessary is that we put in place the international force that allows us to deal with the underlying issue and put the Government of Lebanon fully and properly in control of the whole of the Lebanon, so that Lebanon can get back on its feet and Israel can be secure."
Mr Blair stressed the need to resolve the Israeli-Palestinian dispute which he said lay at the root of the current crisis. He pledged to work "tirelessly" to revive the Middle East peace process and the Road Map to a two-state solution for the area.
"This is a first step," he said. "There's still much to be done.
"But there is no reason why this resolution should not be adopted now and we have the cessation of hostilities literally within the next couple of days."
Since announcing the postponement of his planned holiday, Mr Blair has been engaged in a round of telephone diplomacy to try to assist the agreement of a draft text.
He has spoken to the prime ministers of both Israel and Lebanon, as well as French President Jacques Chirac, UN Secretary General Kofi Annan and the premiers of Italy, Sweden and Spain. Downing Street said he had no immediate plans to leave for his summer break. The resolution to be discussed by the Security Council calls for "a full cessation of hostilities based upon, in particular, the immediate cessation by Hezbollah of all attacks and the immediate cessation by Israel of all offensive military operations".
It asks Israel and Lebanon to agree to a set of principles to achieve a long-term peace.
The terms include an arms embargo that would block any entity in Lebanon except the Lebanese Government from obtaining weapons from abroad. The clause is designed to prevent Hezbollah from receiving arms from Syria and Iran, believed to be the militia's main suppliers.
Other principles include the disarmament of Hezbollah and the creation of a 20-kilometre buffer zone between the Israel-Lebanon border and the Litani River.
The existing Unifil UN force would monitor the ceasefire until a second resolution establishes a new stabilisation force for the area, expected to be led by France.
Fighting continued in Lebanon this weekend, with Israeli commandos battling Hezbollah guerillas in the southern port of Tyre while warplanes attacked capital Beirut. Across the country, at least eight Lebanese and one Israeli solider were killed, while Hezbollah rockets killed three women in Israel.
It was not immediately apparent how ready the war-ring sides were to comply with any UN resolution. Israel has previously suggested it would not withdraw from southern Lebanon until the new peace-keeping force is deployed, while Hezbollah has said it will cease fire only when Israeli forces have left the country.
A Hezbollah member of the Lebanese Cabinet, Mohammed Fneish, yesterday said: "We abide by (the resolution) on condition that no Israeli soldier remains inside Lebanese land. If they stay, we will not abide by it."