Thai Prime Minister Yingluck Shinawatra has faced three months of street demonstrations demanding her elected government step down.
Thailand's ruling party has called for controversial elections to go ahead, despite widespread disruption to advance voting by opposition protesters who have besieged polling stations and stopped hundreds of thousands from casting ballots.
Prime Minister Yingluck Shinawatra has faced nearly three months of mass street demonstrations demanding her elected government step down to make way for an unelected "people's council" that would oversee reforms aimed at curbing the dominance of her billionaire family.
Ten people have been killed and hundreds injured in grenade attacks, drive-by shootings and street clashes since the protests began at the end of October.
An anti-government rally leader was shot dead in broad daylight on Sunday while giving a speech from the back of a pickup truck in a Bangkok suburb.
Yingluck is due to meet election authorities on Tuesday to discuss a possible delay to the February 2 general election, after the Constitutional Court ruled that the polls could legally be pushed back because of the civil strife.
But the head of her Puea Thai Party said on Monday he opposed a postponement and accused the Election Commission (EC) of not doing enough to ensure an orderly vote.
"The EC is authorised to hold the election and Puea Thai as a political party fielding candidates does not agree with a postponement or delay to the election," Jarupong Ruangsuwan said.
"The EC is stubborn and wants the election to be postponed," he said. "I think the Constitutional Court and the EC are coordinating with the protesters."
It was unclear whether his view reflected that of the government, which said it was ready to listen to the poll body's comments at Tuesday's meeting.
About 440,000 people out of two million registered for advance voting were prevented Sunday from casting their ballots, the election commission said.
Protest leader Suthep Thaugsuban has threatened to "close every route" to polling stations again this coming Sunday, saying the election would not be allowed to take place.
The opposition Democrats are boycotting the February polls, saying reforms are needed to ensure the election is truly democratic and to prevent abuse of power by the next government.
In an interview, Democrat Party leader Abhisit Vejjajiva said on Monday that the opposition would consider taking part in a delayed vote.
He called for talks to draw up a "roadmap where reforms can be initiated and we can set a reasonable timeframe for elections that would be accepted by all sides".
Abhisit distanced himself from the protesters' proposal for an unelected "people's council" to run the country, saying that was not the demand of his party.
But he added that Yingluck "does not have the credibility" herself to oversee the reform process.
The kingdom has been bitterly divided since Yingluck's older brother, the then-prime minister Thaksin Shinawatra, was overthrown by royalist generals in a coup more than seven years ago.
Critics accuse the billionaire tycoon-turned-politician of controlling his sister's government from Dubai, where he lives to avoid prison for a corruption conviction.