British Prime Minister Tony Blair says he hopes a peace plan will be drawn up within days that will lead to an "immediate cessation of hostilities" in Lebanon.

Blair, who is facing increasing criticism at home for joining U.S. President George Bush as the only Western leaders not to publicly call for a ceasefire, said what was happening in Lebanon was a "catastrophe," but that innocent Israeli civilians had been killed too.

Speaking alongside Iraqi Prime Minister Nouri al-Maliki, Blair said a ceasefire would only work if conditions were first put in place to ensure both sides respected it.

"I don't want the killing to go on. I want the killing to stop now.," Blair told a news conference in Downing Street Monday. "But it has got to happen on both sides. It is not going to happen on both sides without a plan to make it happen."

Although Blair has been one of the prime backers of an international force, Britain is unlikely to contribute to one in Lebanon because its military is stretched in both Afghanistan and Iraq.

"There have been as you might expect over the past few days enormous diplomatic efforts to get us to the point where I hope at some point within the next few days we can say very clearly what our plan is to bring about an immediate cessation of hostilities ..." Blair continued.

When asked to give details of his plan, he said it consisted of an end to shooting, the return of kidnapped Israeli soldiers and also an international force to act as a "buffer," a proposal he first made during a meeting of leaders of the G8 group of industrial countries in Russia last week.

"That is the plan we've been working on and we've been working on it since the G8. If somebody has a better plan then I'd like to hear it," Blair added.

Blair's remarks came as Britain's opposition Liberal Democrats party called on him to suspend arms exports from the UK to Israel "in light of disproportionate military action by Israel in Lebanon and Gaza".

Liberal Democrat leader Sir Menzies Campbell said that over the last 18 months, the government had licensed the export of arms to Israel worth over $45 million US, including components for naval light guns, military utility helicopters, aircraft radars and electronic warfare equipment.

"The government must now comply with its own arms export rules and institute an immediate suspension of all U.K. arms exports to Israel," Campbell wrote in a letter to Blair.

"Kofi Annan has said attacks in Lebanon are inflicting collective punishment on the Lebanese people and the UN Emergency Relief Co-ordinator has described attacks on Beirut as a 'violation of humanitarian law'."

There was no immediate response from Blair's office on Campbell's call, the Associated Press reported.

Meanwhile, Iraqi Prime Minister Nouri al-Maliki warned violence in Lebanon could lead to further extremism in the Middle East.

"What is going on in Lebanon will be a great push toward fundamentalism," he told the London news conference standing alongside Blair. "What is going on in Lebanon and what we in Iraq see on television and other Iraqis see on television will backfire on the stability process in Iraq."

U.S. Secretary of State Condoleezza Rice held talks with Lebanon Prime Minister Fouad Siniora in Beirut Monday as part of her Middle East tour to discuss the crisis.  Rice said there was an "urgent" need for a ceasefire, but that conditions on both sides had to be right.

Israel says it will not stop raids on Lebanon until it has destroyed Hezbollah's ability to strike Israel. At least 370 people in Lebanon and 37 Israelis have died since Israel began attacks 13 days ago following a Hezbollah cross-border raid in which two Israeli soldiers were captured.