Libya's government today shrugged off the departure of Foreign Minister Mousa Kousa, saying Muammar Gaddafi's regime "does not depend on individuals".
This was the government's first admission of the defection.
The defection of the foreign minister, the most senior figure to jump ship since the uprising against Gaddafi's iron-clad 41-year rule erupted more than six weeks ago, was widely seen today as an indication that the strongman's regime is crumbling.
Kousa arrived at Farnborough Airfield, west of London, yesterday.
British Foreign Secretary William Hague insisted that Kousa, who has been blamed for atrocities including the 1988 Lockerbie bombing, had not been offered immunity from prosecution in British or international courts.
"Mousa Kousa is not being offered any immunity from British or international justice," Hague told reporters.
He said the minister was being interviewed "voluntarily" by British officials.
"He said that he is resigning his post. We are discussing this with him."
Kousa's defection was a "sign that the regime's days are numbered," defected immigration minister Ali Errishi told France 24 television today.
"It is the end... it is a blow to the regime (and) others will follow," said Errishi who himself defected soon after the insurrection began.
"Kousa was his most trusted aide. Gaddafi no longer has anybody. It's just him and his kids."
Libya’s former deputy ambassador to the UN, Ibrahim Dabbashi, told France 24 in a separate interview that Kousa's defection "was very important at this stage because he knows a lot of secrets of the regime. He has been working with the Gaddafi regime for a long period now."n.