It would be "inconceivable" for Colonel Muammar Gaddafi to remain in charge of Libya, Prime Minister David Cameron has said.

But Mr Cameron ruled out regime change, saying it was up to the Libyan people to decide "who governs them and how they are governed".

The Prime Minister made his comments after he was asked by senior Tory MP Edward Leigh whether a deal could now be struck with the Libyan leader if he was prepared to implement a ceasefire.

Mr Leigh said: "Would you confirm that our mission is entirely humanitarian and there is the genesis of a deal here if Gaddafi is just prepared to hold what he has in Tripoli and we could then achieve a compromise and an end to this war?"

Mr Cameron replied that Gaddafi could "play his part" in helping the United Nations to enforce Resolution 1973, but in the end he would have to go.

The Prime Minister told MPs in the Commons: "Britain's role is very clearly set out in UN Resolution 1973, which is to work with others to stop the attacks on civilians.

"It is not about regime change, it is for the people of Libya to decide who governs them and how they are governed.

"We have also always been clear that if Gaddafi declared a ceasefire where he was actually removing his troops from the towns and cities that he invaded, then clearly that would be playing his part in resolving resolution 1973.

"Where I have always gone on and said I can't see a future for Libya where Gaddafi is still in place, is for the very simple reason that if you look at what this man has done over the last 100 days, is that although he has had every opportunity to pull back and put in place a ceasefire, all he has done is more shelling, attacking, murdering, sniping his own citizens."

Foreign Secretary William Hague had earlier hailed the issue of an international arrest warrant for Gaddafi, saying it showed he had "lost all legitimacy".

Photo by che 1899, Press Association