The move was “a significant blow” to Qaddafi, a British government source told Reuters.
Koussa is one of the most senior members of Qaddafi’s inner circle to defect — a major setback for the Libyan leader who faces a revolt against his 41-year rule in the North African oil producing desert state as well as Western air strikes.
Koussa, who was involved in talks that led to the freeing by the British government of the man convicted over the 1988 Lockerbie bombing, is resigning his post and the British government said it hoped more senior figures would join him.
“He traveled here under his own free will. He has told us he is resigning his post,” a Foreign Office spokesman said in a statement. “We are discussing this with him and we will release further detail in due course.”
He was reported to be being debriefed by British intelligence and foreign ministry officials.
“Koussa is one of the most senior figures in Qaddafi’s government and his role was to represent the regime internationally — something that he is no longer willing to do,” the spokesman said.
“We encourage those around Qaddafi to abandon him and embrace a better future for Libya that allows political transition and real reform that meets the aspirations of the Libyan people,” the Foreign Office said.
Koussa arrived at Farnborough airport in southern England on a flight from Tunisia, Britain’s Foreign Office said.
Meanwhile, Reuters are reporting that President Barack Obama has signed a secret order authorizing covert US government support for rebel forces seeking to oust Libyan leader Muammar Qaddafi, government officials told Reuters on Wednesday.
Obama signed the order, known as a presidential “finding,” within the last two or three weeks, according to government sources familiar with the matter.
Such findings are a principal form of presidential directive used to authorize secret operations by the Central Intelligence Agency. This is a necessary legal step before such action can take place but does not mean that it will.
The CIA and the White House declined immediate comment.
News that Obama had given the authorization surfaced as the President and other US and allied officials spoke openly about the possibility of sending arms supplies to Qaddafi’s opponents, who are fighting better-equipped government forces.
The United States is part of a coalition, with NATO members and some Arab states, which is conducting air strikes on Libyan government forces under a UN mandate aimed at protecting civilians opposing Qaddafi.
Interviews by US networks on Tuesday, Obama said the objective was for Qaddafi to “ultimately step down” from power. He spoke of applying “steady pressure, not only militarily but also through these other means” to force Qaddafi out.
Obama said the US had not ruled out providing military hardware to rebels. “It’s fair to say that if we wanted to get weapons into Libya, we probably could. We’re looking at all our options at this point,” he told ABC News anchor Diane Sawyer.
In Washington, Secretary of State Hillary Clinton insisted to reporters on Wednesday that no decision had yet been taken.
US officials monitoring events in Libya say neither Qaddafi’s forces nor the rebels, who have asked the West for heavy weapons, now appear able to make decisive gains.
While US and allied airstrikes have seriously damaged Qaddafi’s military forces and disrupted his chain of command, officials say, rebel forces remain disorganized and unable to take full advantage of western military support.
