A weekend parliamentary by-election in Bangkok is seen as a crucial test of the Thai government's efforts to promote national reconciliation, after the military brought an end to anti-government protests in May. The opposition hopes its candidate, who remains in jail, will draw a strong sympathy vote at the polls.

On the outskirts of Bangkok, Sunday's by-election is widely seen as a proxy battle between the government and the anti-government Red Shirt movement, which staged protests in central Bangkok for two months before being dispersed by the army on May 19.

The two months of violent protests left 90 people dead and almost 1,900 injured in the most severe political turbulence in almost 20 years.

The governing Democrat Party of Prime Minister Abhisit Vejjajiva opposes the Puea Thai Party, which is closely aligned with ousted former leader Thaksin Shinawatra.

The Puea Thai Party nominated candidate, Korkaew Pikulthong, a Red Shirt leader who remains jailed on terrorism charges.  He is one of several Red Shirt leaders being detained for their involvement in the demonstrations.   

Party member Kudeb Saikrajang says party officials hope nominating a former Red Shirt leader will help win support through voter sympathy.

"Right now some people might think - of its half and half [50/50] - because we have the support by the Red Shirt movement," said Kudeb Saikrajang. "And those Red Shirt people are campaigning very, very hard for the party.  So to field Khun Korkaew, it's the best thing we can do."

Panich Vikitsreth, a former investment banker and deputy governor of Bangkok, is the Democrat Party candidate.   

Baranuj Sumatharak, a Democrat Party spokesman, says the real test is whether Thai democracy can resume peacefully through the electoral process.

"We have done, to the best success possible, to try to bring politics back to policy, and hopefully the people will see that this signifies a transition back from being out on the streets, back to the democratic process," said Baranuj Sumatharak. "We're hopeful that the results will prove that."

The Democrat Party is hoping for a repeat of a landslide victory in local government elections in Bangkok in early June.  But at the last national elections in 2007, the party won the seat by a slim majority over a former pro-Thaksin party.

Baranuj says voters will also be indicating their support for the government's national reconciliation plans, which include the setting up of several committees to investigate the bloodshed in April and May and to promote social reforms.

But the Thai language newspaper Thai Rath said in a recent commentary the violence surrounding the protests is still haunting the government.  A state of emergency remains in place throughout more than a dozen provinces including the capital Bangkok.

The paper said only a landslide victory in the by-election will enable the Democrat Party to regain public confidence and remain in power for another year.  National elections in Thailand are due to be held before the end of 2011.