In a rambling televised speech in Tripoli, the embattled despot lashed out at Europe and the United States and declared they faced 'another Vietnam' if they launch military action.

'They will set foot in hell - worse than Afghanistan,' he said. 'We will enter a bloody war and thousands of Libyans will die if the United States enters or Nato enters. We will fight until the last man and woman. 'We are ready to hand out weapons to a million, or two million or three million, and another Vietnam will begin. It doesn't matter to us. We no longer care about anything.'

But senior government sources have confirmed that contacts with Mr Blair have been conducted 'at the highest levels' - code for Mr Cameron. A senior Whitehall official said Mr Blair's office warned Downing Street he was planning to talk to the Libyan despot, telling him it was time to go. 'Then Blair got in touch again to say that he had spoken to Gaddafi and said he was going to speak to him again.'

Since then, Mr Cameron has discussed the situation personally with Mr Blair. A second senior source said: 'It's not a case of Cameron using him as a conduit to Gaddafi, it's a case of picking his brains.'