BANGKOK - THAILAND'S Parliament may find itself in a legal limbo, which throws into doubt the selection of a new prime minister and Cabinet, and the future of the caretaker government.

With the dissolution of three parties in Thailand's ruling coalition by the Constitutional Court this week, more than 35 party list members, along with directly elected MPs, have moved to Puea Thai, a shell party activated to accommodate them so that the present governing set-up can be kept alive.

But now that plan has run into a hitch: the president of the Senate has a petition from 40 senators challenging the legality of the switch. It is likely to be forwarded to the Constitutional Court on Monday.

Under the Thai system, apart from MPs voted into particular wards, there are also party list MPs who get into Parliament based on the number of votes for the party.

The anti-government senators argue that these MPs were voted in on the basis of their membership in the dissolved People Power Party (PPP) and not Puea Thai.

If the court takes this view, the MPs may be disqualified, severely denting the ruling coalition's numbers in Parliament, creating gridlock and throwing open several other options.

Before the dissolution of the PPP-led coalition for electoral fraud, the PPP had 233 seats out of 480 in Parliament. Its partners, the Chart Thai and Matchima Thipataya, have a combined 45, making a total of 278.

Almost all these MPs have signed up for the new Puea Thai party, in a process that is still ongoing.

The opposition Democrat Party has 165 MPs, while other small parties - or vacant or inactive seats - make up the rest.

Of the former PPP's seats, 34 were taken up by party list MPs. Chart Thai had four. If the court rules against the switch, the ruling coalition stands to lose 38 seats, leaving it with 240 - just half of Parliament's 480.

One way out of the deadlock is dissolution of the House and fresh elections.

But the foremost solution being considered is a 'national unity' Cabinet drawn from all parties.

The army is in favour of this because it would avoid re-igniting the conflict between loyalists of former premier Thaksin Shinawatra and the People's Alliance for Democracy (PAD), which has threatened to protest again if a pro-Thaksin premier is appointed.

It is in the army's interest to defuse the conflict because it may be sucked in if it spirals out of control - a move that would meet resistance in the streets at home and draw condemnation abroad.

The army is also tacitly on the side of the PAD, which itself has the backing of the powerful Bangkok elite.

A 'national unity' arrangement could feature the Democrat Party, which is favoured by the Bangkok elite.

A group of more than 40 ruling party legislators headed by former PPP MP Newin Chidchob could be a key swing factor: It is said to favour the election of senior Democrat Party figure Chuan Leekpai, who, however, has deferred to party leader Abhisit Vejjajiva.

But the Chuan suggestion may be a ploy to divide the Democrats, a source said. The Newin faction actually backs the politician's father, the veteran Chai Chidchob, Speaker of the House.

Such machinations by various factions further complicate the outlook.

The Puea Thai party is against a 'national unity' arrangement, partly because collaborating with the Democrats is anathema, and partly because such a Parliament could ram through amendments in the Constitution that the PAD demands.

These would essentially dilute the one-man-one-vote system in favour of a semi-appointed Parliament.

The formula is seen as elitist and setting back the development of democracy in Thailand by decades.

It would also sound the death knell for the Puea Thai's electoral chances.

A session of Parliament earlier set for Monday to elect a new premier has been postponed, and may have to be delayed for several days for the legal issues to be resolved.

nirmal@sph.com.sg