Tony Blair privately urged Libyan dictator Colonel Gaddafi to stand aside as rebellion erupted against his regime, according to newly released correspondence.
The former prime minister advised Gaddafi to find "a safe place to go" as part of a "managed" process of political change before the situation reached "the point of no return".
The details of Mr Blair's intervention have emerged from the emails of former US secretary of state Hilary Clinton released under the American freedom of information laws.
They include a message from Mr Blair's head of strategy Catherine Rimmer to Jake Sullivan, a senior adviser to Mrs Clinton - dated 25 February 2011, shortly after the uprising began - briefing him on a telephone conversation Mr Blair had had that day with Gaddafi
Ms Rimmer said Mr Blair was making the call "very privately" and he had delivered a "very strong message" that the violence had to end and Gaddafi stand aside to allow a peaceful transition to take place.
She quoted Mr Blair as saying: "The absolute key thing is that the bloodshed and violence must stop.
"If you have a safe place to go then you should go there, because this will not end peacefully unless that happens and there has to be a process of change. That process of change can be managed and we have to find a way of managing it.
"I have talked to people and everyone wants a peaceful end to this."
Mr Blair was said to have told Gaddafi that he needed to make clear that he was ready to engage in a process of change and that he would tell his forces not to use violence against the people.
He then appeared to indicate he was ready to intervene with Western governments in an attempt to secure a peaceful resolution to the crisis.
"The US and the EU are in a tough position right now and I need to take something back to them which ensures this ends peacefully," he is quoted as saying.
"If people saw the leader standing aside they would be content with that. If this goes on for another day/two days we will go past the point. I'm saying this because I believe it deeply. If we can't get a way through/out very quickly this will go past the point of no return."
The latest disclosure is likely to intensify calls for Mr Blair - who ended Gaddafi's international isolation with his so-called "deal in the desert" in 2004 - to give evidence to a Commons inquiry into Britain's foreign policy towards Libya.
The chairman of the Commons Foreign Affairs Committee Crispin Blunt has already said he would like Mr Blair to appear before them after a new biography of David Cameron claimed he tried to intervene with Downing St during the uprising.
According to Cameron At 10, by Sir Anthony Seldon, Mr Blair telephoned No 10 to say that he had been contacted by "a key individual close to Gaddafi" and that the Libyan dictator wanted to "cut a deal" with Britain.
Mr Cameron - who ordered RAF air strikes against Gaddafi's forces - did not take up the offer, the book said.
The rebels finally overran the capital, Tripoli, in August 2011. Gaddafi was captured and killed two months later.