Five million Thais sign up for Thaksin pardon - organisers

Supporters of ousted Thai prime minister Thaksin Shinawatra hold a poster of him during a rally in Bangkok July 31, 2009.

BANGKOK (Reuters) - "Red-shirt" supporters of former Thai premier Thaksin Shinawatra ended a rally in Bangkok on Saturday, claiming more than 5 million signatures for a petition seeking royal clemency for the fugitive billionaire.

Demonstrators from the United Front for Democracy against Dictatorship (UDD) rallied overnight near Bangkok's Grand Palace to support an appeal to King Bhumibol Adulyadej to allow Thaksin to return from exile a free man.

Nattawut Saikeu, a UDD leader, told supporters that 5,411,928 people had signed the petition by the time it closed at midnight on July 31.

"This is the fight to bring back democracy to the people and we will win in the end ... We do not care if we are to die or be put in jail," he told the crowd.

Thaksin won landslide election victories in 2001 and 2005 but was overthrown by the military in a 2006 coup. He was found guilty of corruption last October and sentenced in absentia to two years in prison.

He denies the charges and still commands a loyal following, especially among the rural poor.

Thaksin called in to the rally late on Friday and thanked all those who had signed the petition.

"I hope I can be among you soon. I am 60 this year and it is my hope that I can return home when I turn 61," Thaksin told the cheering crowd estimated at about 30,000.

The petition, which may be submitted next week, calls on the 81-year-old king to pardon Thaksin to help pave the way for his political return.

The campaign has caused outrage among royalists and political opponents, who accuse Thaksin and his backers of insulting the revered monarch by trying to drag him into a political dispute.

King Bhumibol, the world's longest-reigning monarch, is officially above politics but has intervened at times of crisis.

The UDD has staged frequent rallies around the country demanding that Prime Minister Abhisit Vejjajiva resign and calling for new elections, which analysts say the Thaksin-backed Puea Thai party would be favourites to win.

Demonstrations by the "red shirts" turned violent in April and prompted Abhisit to declare a state of emergency in Bangkok in response to the country's worst street clashes in 15 years.

The UDD says Abhisit is an illegitimate army stooge who came to power only with the help of military-orchestrated parliamentary defections from Thaksin's side last year.

(Additional reporting by Viparat Jantraprap)