BANGKOK - Several thousand red shirt protesters rallied in Bangkok amid tight security on Saturday to demand the Thai government submits its petition seeking a royal pardon for fugitive former premier Thaksin Shinawatra.

The United Front for Democracy Against Dictatorship (UDD) accused the government of dragging its heels in forwarding the petition, signed by 3.5 million Thais, to King Bhumibol Adulyadej, who has been undergoing treatment in hospital since September 19 for fever and lung inflammation.

The 81-year-old king's health was improving and he was not in danger, his youngest daughter, Princess Chulabhorn, said on Friday in the first public comment by a royal family member since he was admitted.

Thai stocks plunged a combined 7.2 percent on Wednesday and Thursday on concerns about the health of the world's longest-reigning monarch, who is seen as a semi-divine unifier by his people, but rebounded 3.5 percent on Friday.

The UDD believes the self-exiled Thaksin is a victim of a vendetta by his powerful opponents in the military and the Thai establishment, who they say plotted the coup that toppled him and ensured he was convicted of graft to keep him sidelined.

The government is still deliberating whether to submit the clemency plea, which Thaksin's supporters hope will aide his political comeback, a scenario analysts say would deepen rifts and further destabilize Southeast Asia's second-biggest economy.

GOVERNMENT WARNED

We are here today to send a warning to the government, UDD coordinator Jatuporn Prompan told the red-shirted crowd. The government is trying to delay the petition seeking the royal pardon for Thaksin.

The UDD rally was the sixth since April, when three weeks of protests led to anarchy in Bangkok and a security crackdown that sparked the country's worst violence in 17 years.

The mass rallies have prolonged Thailand's polarizing four-year political crisis, spooking investors and prompting credit ratings downgrades as a result of continued uncertainty.

Thousands of riot police and troops empowered by a tough internal security law maintained a heavy presence around the government's headquarters on Saturday, where the crowds were growing ahead of a scheduled video address by Thaksin from Dubai.

The demonstration was another sign of Thaksin's mesmerizing influence on the rural masses, who helped deliver two landslide election wins and have remained loyal to him, despite a graft conviction and a slew of other corruption charges.

The 60-year-old billionaire, a former telecoms tycoon and English Premier League soccer club owner, is also backed by the Puea Thai Party, Thailand's main opposition, which analysts say has big support and would likely win most votes in the next election.

Prime Minister Abhisit Vejjajiva has refused to heed UDD calls to dissolve the house and call a snap election, saying no vote will be held until Thailand's economy has recovered and a referendum on constitutional amendments is carried out.

(Writing by Martin Petty; Editing by John Chalmers)

Thailand