BANGKOK, May 4 (AFP) - Thailand's fugitive former premier Thaksin Shinawatra has hired an international law firm to help the anti-government protest movement holding mass rallies in Bangkok, the company said Tuesday.

Amsterdam & Peroff, which has office in Toronto, London and Washington, said it had been appointed by Thaksin "to assist in the current contentious struggle for the restoration of democracy and rule of law" in Thailand.

"We are pleased to be retained by Prime Minister Shinawatra to work on this urgent matter, and we acknowledge the challenging complexity and sensitivity of the political crisis unraveling Thai society," said Robert Amsterdam, a founding partner of the law firm, said in a statement.

"It is our intention to explore every legal avenue to assist this pro-democracy movement, and urge the international community not to tolerate the government's violent crackdown on peaceful protesters."

Thaksin, who was in office between 2001 and 2006, was ousted in a bloodless military coup and lives overseas to avoid a jail term for corruption.

Many of the "Red Shirt" anti-government protesters who have been rallying in Bangkok since mid-March seek the return of the telecoms tycoon-turned-politician, hailing his policies for the masses.

There have been a series of tense confrontations between the demonstrators and the security forces in Bangkok, where 27 people died and nearly 1,000 were injured in unrest last month.

Arrest warrants have been issued for many leading Red Shirts, who have been defying a ban on rallies under a state of emergency in the city.

The movement was on Tuesday considering Prime Minister Abhisit Vejjajiva's proposal to hold elections on November 14 to end the stand-off, and a government source said an amnesty might be discussed for protest leaders.