Syria’s most senior diplomat in London has defected, Britain’s Foreign Office said Monday. Khaled al-Ayoubi, the charge d’affaires in London, told officials that he was no longer willing to represent the regime of President Bashar Assad.

“Mr. al-Ayoubi has told us that he is no longer willing to represent a regime that has committed such violent and oppressive acts against its own people,” the Foreign Office said. “We urge others around Bashar Al-Assad to follow Mr. al-Ayoubi’s example; to disassociate themselves from the crimes being committed against the Syrian people and to support a peaceful and free future for Syria,” the Foreign Office Spokesperson added.

Al-Ayoubi’s departure represents the latest in a series of diplomatic and other defections from Assad’s regime. Recently Turkey reported that the deputy head of security for Syria’s Latakia region, a regime stronghold, had defected as well. The brigadier general was among a group of 12 Syrian officers who crossed into Turkey on Sunday, a Turkish official told reporters .

Britain withdrew its ambassador to Damascus earlier this year. Syria’s ambassador, Sami Khiyami, also left London earlier this year.

Meanwhile, in Syria, Syrian government troops continue to besiege Aleppo, with refugees describing the city to reporters as being beset by incessant shelling amid low food and petrol supplies and soaring black market prices for everyday staples.

The UN have said 200,000 Syrians have left Aleppo over the past 10 days, as the government continues its assault with mortars, tanks and helicopter gunships on neighbourhoods seized by the rebels.

The conflict in Syria, which began in March 2011, has now cost more than 19,000 lives, according to the UK-based Syrian Observatory for Human Rights.