David Cameron today called for a "proper orderly transition" to democratic government in Egypt.
The Prime Minister said he had warned President Hosni Mubarak in a phone conversation that a repressive response to the protests which have convulsed Egypt over the past week would "end badly" for his country and the world, and urged him to opt instead for reform.
But Mr Cameron stopped short of saying that Mr Mubarak should stand down, insisting it was not for the UK to choose who should lead other countries.
He and US President Barack Obama agreed, in a telephone conversation last night, that they wanted to see Egypt offer its people greater rights and freedoms, as well as the protection of the rule of law.
Protesters were camped out in the streets of Cairo this morning, after six days of mass demonstrations demanding an end to Mr Mubarak's three-decade rule.
There was little sign of an end to protests despite a show of strength by the military yesterday and more than 100 deaths over the past week.
Mr Cameron called on the Egyptian authorities to "go down the path of reform and not repression".
He told BBC1's Breakfast: "I have spoken to President Mubarak and had a conversation with President Obama last night, and we were very much agreed that we want the response of the Egyptian government to be that there needs to be a proper orderly transition to a more democratic situation, where there are greater rights, greater freedoms, better rule of law and that sort of reform, to show to people in Egypt that their concerns and their aspirations are being listened to.
"It is very important that whether it is President Obama or me, we are not saying who should run this country or that country.
"But I think in the conversations we have with President Mubarak and others it is sensible to say 'You do have a choice here. This repression - if you opt for that, that will end badly for Egypt, badly for the world. It is the wrong choice'."
Foreign Secretary William Hague will meet his EU counterparts in Brussels today for talks on the situation in Egypt at which he said they would "collectively underline the need for change".
Mr Hague told BBC Radio 5 Live that Britain was calling on the Egyptian leadership to "embrace change, to establish a broadly-based government to show that there will be a proper transition to free and fair elections".
As the largest Arab country and Israel's most powerful neighbour, Egypt played a "pivotal" role in the Middle East peace process and instability in Cairo could have a major impact on the stability of the entire region, warned Mr Hague.
The emergence of a regime in Egypt which did not recognise Israel would be "a major setback for the Middle East peace process", he added.
But he said he did not believe Israel was high among the protesters' concerns: "I think this is about people wanting freedom, economic opportunities and freedom of expression. I suspect those are their concerns, rather than international relations."
Demonstrators in Egypt have been critical of the role of the West in propping up the Mubarak regime financially.
But Mr Hague said: "They haven't been propped up unconditionally. They have been receiving the message from Western nations that change is necessary. What has happened in the last week truly underlines that."
Middle East peace envoy Tony Blair told Radio 5 Live's breakfast programme that President Mubarak needed to engage in a process of "managed change".
The former prime minister said: "People want change but they don't want chaos. There's going to be change - there's no doubt about that.
"And there will be a move, I think, to free and fair elections. But it's got to happen in such a way that political parties have got a chance to compete properly in those elections and so that there is a sense of order and responsibility as this process of change gets under way."
Mr Blair said he did not believe most Egyptians wanted to see the fundamentalist Muslim Brotherhood win power.
"I don't think there is a majority for that in Egypt, in fact," he said.
"I don't think that's the risk. Funnily enough, I don't think they would win an election. I think the danger is if you get chaos and then out of that chaos comes the wrong sort of change."
It was "perfectly possible that you (will) get a democratic government that is prepared to work with the government of Israel to bring about a Palestinian state", he said. A new regime which refused to recognise Israel would be "very bad".
Warning against demonisation of the Egyptian President, Mr Blair stressed that "Hosni Mubarak is not Saddam Hussein" and said he had done "an immense amount" for the peace process.
But he said it was not "sustainable" for out-of-touch elites to go on "governing in the way that they've been governing for decades".Reuse content