BANGKOK, Feb 26 (Reuters) Three Thai opposition parties met separately today to decide whether to boycott a snap general election as 5,000 police prepared to keep the peace at another major rally against Prime Minister Thaksin Shinawatra.
The Democrat, Chart Thai and Mahachon parties yesterday agreed to work together against Thaksin, a former tycoon they accuse of undermining the checks and balances of the constitution and tailoring policy to suit his family's business.
But they did not agree immediately on a boycott aimed at undermining the legitimacy of Thaksin, who called the April 2 election a year after winning a second landslide victory and expects to ride rural support back into power.
''Why do we have to run in a general election that will not be free and fair,'' Chart Thai deputy leader Somsak Prisnanantakul told a Bangkok radio station ahead of his party meeting to decide on a boycott.
As the opposition met, police set up checkpoints around Bangkok to search for weapons in buses and trucks taking people to the anti-government rally in front of the glittering Grand Palace.
''We are not stopping them from coming to the capital to rally, but we are preventing potential unrest from clashes between government supporters and opponents,'' said National Police Force spokesman Ajiravid Subarnbhesaj.
The organisers of the rally, a coalition of groups outside parliament, had hoped to draw 100,000 people to the rally.
But the announcement of a snap election would probably mean only about 50,000 protesters, which would still be the biggest anti-government demonstration in 14 years would turn out, Ajiravid said.
The anti-government campaign run by the People's Alliance for Democracy (PAD) has caught fire since Thaksin's relatives sold Shin Corp, the telecommunications empire he founded, to a Singapore state firm for a tax-free 1.9 billiondollars last month.
The PAD was joined last week by the man who brought Thaksin into politics, ascetic 70-year-old former general Chamlong Srimuang, leader of a successful ''people's power'' revolt against a military-led government in 1992 in which 50 people were killed.
His presence raised fears of violence and the PAD has taken up his call for today to be only the start of a mass demonstration which should continue until Thaksin quits.
''Trust me, this is the right way,'' Chamlong said yesterday.
''The important thing is people need to come to the rally. The greater the number of people either on February 26, 27 or 28, the higher chance we have of winning,'' he said.
Thaksin's Thai Rak Thai (Thais Love Thais) said the three opposition parties would betray democracy by boycotting the election, which Thaksin is expected to win, albeit with fewer than the 377 of the 500 lower house seats it won a year ago.
''This means the opposition doesn't believe in democracy, in the existing rules of the constitution, drafted by the people,'' said party spokesman Suranand Vejjajiva. ''The opposition is tearing up the People's Constitution.'' REUTERS SB BS1121