The pro-military Palang Pracharath Party, the powerhouse that leads the government coalition, scooped up another seat yesterday in a by-election in the central province of Kamphaeng Phet, one day ahead of a no-confidence parliamentary debate.

The expected victory will give the party and the coalition another boost in the light of this week's censure debate targeting six top government officials, including Prime Minister Prayut Chan-o-cha, said political scientist Wanwichit Boonprong of Rangsit University, although the winning candidate will not be able to vote in Parliament at the end of the week until the Election Commission (EC) clears his MP status.

"This may even encourage some MPs from other parties to join Palang Pracharath and strengthen the party further," said Assistant Professor Wanwichit.

The winner, Mr Petchpoom Aponrat, 27, beat his main rival Kampon Panyakul from Pheu Thai, the biggest opposition party, with 45,687 votes against 37,989, according to the EC's unofficial results.

Of the four by-elections held so far, it was the second win for Palang Pracharath and the third for the government coalition, which now enjoys a comfortable majority of 264 seats in the 500-member Lower House, against 224 seats for the opposition.

Last Friday, 11 Future Forward Party MPs were banned from politics for 10 years by the Constitutional Court over "irregular" loans that party leader Thanathorn Juangroongruangkit issued to the now-disbanded party.

Mr Petchpoom is the son of Vipot Aponrat, 61, the winner in the same constituency in the March general election last year. He was disqualified as an MP after a court sentenced him to four years' jail last September for his role in a violent protest at the Asean Summit held in Pattaya in 2009, which injured over a dozen people and forced the meetings to shut.

A former core member of the Red Shirt, a group of supporters of former prime minister Thaksin Shinawatra who was ousted in a 2006 coup, Vipot was an MP in Thaksin's Thai Rak Thai party, and the party's successor Pheu Thai, before joining the newly founded Palang Pracharath.

Although Mr Petchpoom had no political experience before the election, his victory was largely thanks to the deep connection the locals have for Vipot and Dr Varathep Rattanakorn, a Kamphaeng Phet-born former minister.

"People are generally more attached to individuals than parties," said Prof Wanwichit.