Thousands of supporters of the People's Alliance for Democracy (PAD) supporters gathered outside the British embassy on Tuesday, demanding the British government extradite ex-premier Thaksin Shinawatra to face criminal charges.

The move came after Mr Thaksin and Khunying Potjaman skipped bail and failed to report for a hearing on the Ratchadaphisek land case last week by fleeing to Britian.

PAD core leader Chamlong Srimuang, who led the protesters, said the PAD would like to submit a letter to the British government to ask them to return Thaksin "to receive justice in Thailand."

The letter was handed to a representative of British ambassador, Quinton Quayle.

"Thaksin fled the indictment to London and is planning to seek asylum in Britain," the letter said. "If Thaksin is not brought back to face the charges against him in Thai courts, it will further contribute to the political and democratic deadlock."

The protesters began gathering at Central World shopping centre in Pathumwan at 9am, then headed to the embassy on the corner of Wireless and Ploenchit Roads at mid-morning.

Security measures at the embassy were stepped up while iron barricades were placed around the area, especially at its entrances.

About 500 police officers patrolled the rally.

© Bangkok Post