LONDON - Britain has revoked the diplomatic immunity of Muammar Gaddafi and his family, William Hague confirmed, as the British foreign secretary called for the Libyan leader to step down. Hague said the UK was "working intensively" to establish how many Britons remained in Libya as final evacuation missions were being planned. Asked whether the Libyan leader could remain in power, Hague told BBC1's Andrew Marr Show: "We have here a country descending into civil war, with atrocious scenes of killing of protesters and a government actually making war on its own, so of course it is time for Colonel Gaddafi to go. That is the best hope for Libya. "And last night, I signed a directive revoking his diplomatic immunity in the United Kingdom but also the diplomatic immunity of his sons, his family, his household. So it is very clear where we stand on his status as the head of state." The British Foreign Office believes "very few" Britons remain in the capital, Tripoli, and the second city, Benghazi where HMS Cumberland returned on Sunday to pick up more evacuees. Upwards of 300 are thought still to be in remote desert oil areas, and further military-based rescue missions are thought to be planned. "All I can say at the moment is that we are working intensively to establish who is still in Libya and where they are to see how we can assist with getting them out of there. We continue to urge British nationals to leave Libya," Hague said.He conceded that the FCO had a "very bad day" on Wednesday, when a series of problems saw the first rescue flight stuck on the runway in Britain for many hours. But he paid tribute to staff based at Tripoli airport who did a "fantastic job". Reuters adds: Separately, Peter Mandelson, a close confidant of former British Prime Minister Tony Blair, said that Blair had been in contact with Gaddafi in the last few days. Britain long treated Libya as a rogue state, with hostility deepened by the 1984 shooting of a London policewoman from inside the Libyan embassy and the 1988 Lockerbie airline bombing over Scotland, which killed 270 people, including 189 Americans. Following the 2003 agreement on WMD, Blair helped lead Gaddafi back into the international fold, paving the way for big British business deals in Libya including a $900 million exploration deal by oil major BP. Revoking Gaddafi's diplomatic immunity reinforces that threat because it would mean that any outstanding arrest warrant would apply on British soil. Meanwhile, the foreign minister of Italy, his closest European ally, said on Sunday that the end of Libyan leader Muammar Gaddafi's rule is "inevitable". Foreign Minister Franco Frattini also said a friendship and cooperation treaty between Libya and Italy was "de facto suspended". "We have reached, I believe, a point of no return," Frattini told Sky Italia television. Asked whether Gaddafi should leave power, he said: "It is inevitable for this to happen. Frattini said a UN Security Council resolution imposing sanctions in the form of travel bans and asset freezes on Gaddafi and his family was an important turning point. "It allows us to say that the international community is firmly convinced that the regime cannot, in any way, keep carrying out these acts that have caused the death of thousands and thousands of innocent people," he said. Asked whether the idea of a no-fly zone to defend rebel enclaves from Gaddafi's forces was still on the table, Frattini said: "It is a very important option, for example to prevent retaliation through aerial bombings. Meanwhile, Libya's ambassador to the United States on Saturday threw his weight behind a caretaker government formed by former Libyan justice minister Mustafa Mohamed Abud Ajleil. The Quryna newspaper's online edition reported on Saturday that Abud Ajleil had led the formation of an interim government based in Benghazi, Libya's second city, in the eastern part of the country now largely free of Gaddafi's control. "I am supporting the new temporary government which was formed by ... Mustafa Mohamed Abud Ajleil," Libyan Ambassador Ali Aujali, who this week broke with Gaddafi, told Reuters. Meanwhile, nearly 100,000 people have fled violence in Libya in the past week, streaming into Tunisia and Egypt in a growing humanitarian crisis, the UN refugee agency said on Sunday. They include Tunisians, Egyptians, Libyans and third country nationals including Chinese and other Asians, the UN High Commissioner for Refugees (UNHCR) said in a statement. About half of the 100,000 have gone to Tunisia and half to Egypt.