Prime Minister Srettha Thavisin has brushed aside speculation of the Democrat Party joining the cabinet, saying the government is still strong with 314 MPs.
"Our government is stable and there is no need to add another party or have a cabinet reshuffle," Mr Srettha told reporters at the Bangkok International Trade and Exhibition Centre (Bitec) on Wednesday.
Mr Srettha refused to reply to questions about a cabinet reshuffle now that he is three months into his premiership.
Asked about the possibility the Democrats under new leader Chalermchai Sri-on might switch sides from the opposition to join the coalition, Mr Srettha said: "I will not interfere with other parties as they need to respect their own decision."
"At present, we have a combined force of 314 MPs, which is big enough. We need to give Mr Chalermchai a chance to work and manage his party as he was appointed only 2-3 days ago," he said.
Rumours emerged from reports that the Pheu Thai Party contacted Mr Chalermchai, then the party's secretary-general, about meeting convicted former prime minister Thaksin Shinawatra in Hong Kong in July.
Mr Chalermchai sent Dech-it Khaothong, MP for Songkhla, in response to the invitation amid speculation Thaksin agreed to add the Democrats as one of the coalition partners in exchange for the Democrats supporting Pheu Thai in government. Now the Democrats have Mr Chalermchai as leader, rumours have surfaced that the party will be part of the government.
Meanwhile, Social Development and Human Security Minister Varawut Silpa-archa, in his capacity as leader of the Chartthaipattana Party, one of the coalition parties, said the parties will eventually discuss how they should proceed. A political observer said that despite Mr Chalermchai vowing to stay in opposition, he might think again if the political situation changes.