Two MPs of the Setthakij Thai Party resigned as government whips on Tuesday after their party's loss in a by-election in Lampang province on Sunday.
Phai Lik, MP for Kamphaeng Phet and Setthakij Thai secretary-general, and Boonyasing Warinrak, party registrar and list MP, resigned as government whips with immediate effect, according to media reports.
Mr Phai said people told him during election campaigns that his party should show a clear political stance and his resignation was in response to people's demands.
Mr Boonyasing said his party had distanced itself from the government and denied that his resignation was a political manoeuvre.
Setthakij Thai leader Thamanat Prompow said his party lost the by-election in Lampang because its stance had been unclear. From now on his party would cooperate with the opposition, he added.
Deputy party leader Wichit Plangsrisakul said the result of the by-election showed that voters did not back Setthakij Thai's support for the government.
Earlier Capt Thamanat hinted that his party would only back Deputy Prime Minister Prawit Wongsuwon, leader of the ruling Palang Pracharath Party, in the upcoming no-confidence debate.
Setthakij Thai is home to 18 MPs.
