Libyan foreign minister Musa Kusa has resigned his position in leader Muammar Gaddafi's regime after arriving in London, British officials said.
"We can confirm that Musa Kusa arrived at Farnborough Airport on March 30 from Tunisia. He travelled here under his own free will," the foreign office said in a statement. "He has told us that he is resigning his post. We are discussing this with him, and we will release further detail in due course."
The British government said Kusa was no longer willing to represent Gaddafi's regime internationally.
"We encourage those around Gaddafi 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 statement said.
The government in Tripoli had said Kusa was on a "diplomatic trip" and had not fled.
He left for Britain from the Tunisian island of Jerba near the Libyan border, the Tunisian news agency TAP reported.
Kusa appears to be the highest-ranking official yet to defect from Gaddafi's government, joining numerous ambassadors and other officials who have said that they can no longer represent the regime amid a brutal crackdown on rebels seeking to oust the long-time ruler.