BANGKOK (Reuters) - Thai demonstrators are consolidating efforts to bring down Prime Minister Yingluck Shinawatra and have rejected an election held on Sunday that could renew her mandate.
Due to disruption of the vote, Yingluck could be a mere caretaker premier for months, exposing her to the prospect of intensified protests, legal cases or military intervention.
Following are scenarios for how events might unfold.
Opponents could lodge a raft of complaints with the Election Commission, from fraud and obstruction of voting to the failure to register candidates and the holding of balloting on several dates, which could be deemed unconstitutional.
The Constitutional Court might invalidate the election and order a new one. Yingluck would stay on as caretaker premier with no authority to make decisions on policy or state spending without a parliament to approve them.
The country might be in limbo for months. Protests may continue and the likelihood of violence and military or judicial intervention increases.
Yingluck's Puea Thai Party will likely be the overall winner in the election, but with seats unfilled in many constituencies because of disruption by protesters, there may not be a quorum in parliament to elect a prime minister and form a government.
Protesters may succeed in repeatedly putting off by-elections in constituencies with seats unfilled. Yingluck's position could become untenable as she would face weeks, even months, as a caretaker with only limited authority to set policy and run the economy.
The Election Commission may be able to hold ballots in enough of the outstanding constituencies to ensure a quorum in parliament, and Yingluck is elected prime minister again.
However, her position will remain precarious, with the prospect of legal challenges to the election process as noted above and other court cases lining up. And the protesters may still be disrupting the work of ministries in Bangkok.
Thailand's courts have been unusually active in recent weeks and taken on several cases centred on attempts by Puea Thai to change the constitution, which could result in the dissolution of the party and political bans for its officers.
Some 308 former lawmakers, most of them Puea Thai members, could face a charge of malfeasance for trying to make the semi-appointed Senate a fully elected chamber, which has been ruled illegal. The Constitutional Court is also handling a case about the legality of allowing international agreements to be made by the government without parliament having a say.
The National Anti-Corruption Commission has accelerated an investigation into Yingluck's role as head of a rice price-support scheme that has cost taxpayers billions of dollars and is rife with corruption, according to its critics.
The politicised courts have banned scores of Thaksin's allies in the past and dissolved two of his parties, something referred to as a "judicial coup". It is unclear what rulings could be handed down and whether the Thaksin camp could - as it has twice before - regroup as a new party with new leaders capable of winning an election.
The military has tried to stay neutral, but the top brass shares the protesters' loathing of Thaksin and might be persuaded by the elite and opposition to oust Yingluck.
Violence could intensify in the months ahead, with the potential for more bloody clashes between supporters and opponents of Yingluck, as was seen in north Bangkok on February 1, when seven people were wounded by gunfire or explosions.
If the government is unable to prevent violence, the generals could have a pretext to overthrow Yingluck to avert more bloodshed. The army, however, is probably reluctant to do this given the likelihood of a crippling backlash by the Shinawatras' "red shirt" supporters.
Puea Thai's rule as a caretaker government with limited powers could be severely tested by protests, sabotaged ballots, court cases or clashes. Its position would becomes untenable and the government might agree to step down after some kind of political deal with its opponents, or be forced out altogether.
However, with no sitting parliament to elect a new prime minister and form a new cabinet, a power vacuum is created. Thailand's constitution does not appear to have any clear procedure for such a scenario.
Top judges, or the Senate - which has some legislative powers in the absence of a sitting lower house - could be tasked with forming an interim government to rule until elections can be held and political reforms are introduced, as demanded by anti-government demonstrators.
Editing by Alan Raybould and Robert Birsel