The British Foreign Secretary, William Hague, has said that his government has not offered immunity to his Libyan counterpart, Moussa Koussa, who dramatically flew to Britain yesterday, allegedly in order to defect.
Earlier in his career Mr Koussa served as the head of the Libyan intelligence services. He is currently being questioned by British authorities.
Mr Hague said of Mr Koussa's apparent defection, "His resignation shows that Gaddafi's regime, which has already seen significant defections to the opposition, is fragmented, under pressure and crumbling from within."
The Libyan government has denied claims that Mr Koussa had defected, saying he had flown to London on a diplomatic mission.
Commentators have been somewhat divided about the significance of Mr Koussa's.
The BBC's John Simpson suggested that Mr Koussa had long been considering a defection and had seen his influence decline even before the current uprising. "The key thing is that he was on the out - Col Gaddafi got suspicious of the whole deal done with Britain [over Lockerbie], said it was a plot, and only went through it very reluctantly. Ever since, Col Gaddafi has been saying this was bad, that he was led into it.
"Moussa Koussa also had some kind of battle going on with one of Col Gaddafi's sons and I think he felt it was time to call it a day."
However the Telegraph's Con Coughlin sees more significance in the incident, saying, "This is a man who has not only served as Libya's foreign minister but has been a dedicated Gaddafi loyalist for more than thirty years. As Gaddafi's former intelligence chief, he knows - literally - where the bodies are buried, and his dramatic flight to London is undoubtedly a major coup for the British government and everyone else who wants to see Gaddafi's detestable regime overthrown."
Mr Koussa's arrival in Britain comes just as Colonel Gaddafi's troops appear to regaining ground lost to the rebels earlier in the week.
Airstrikes by RAF and other forces have continued to target pro-Gaddafi forces, especially tanks and armoured vehicles. However NATO, which has taken command of military operations, says that force is only being used to protect civilians and not to aid the rebels in their military campaign.