The Prayut Chan-o-cha government plans to prolong its hold on power and is already testing the waters, key members of the Pheu Thai Party said on Tuesday.
They were responding to the remarks of deputy government spokesman Sansern Kaewkamnerd.
He said on Monday that as long as there were attempts to block the national reform process and cause disorder damaging to the people and officials doing their jobs, the government would stay on to cope with the situation.
Surapong Tovichakchaikul, former deputy prime minister and foreign minister, said some parties were now saying that if the new constitution is not satisfactory to the government then a new reform council and a new constitution drafting committee will be set up to write another charter.
Remarks such as this show that the government may aim to stay for the long term, he said.
Mr Surapong also said the new constitution now being drafted is unacceptable.
Worachai Hema, a leader of the red-shirt United Front for Democracy against Dictatorship, said there has been a testing of the waters about a long tenure for the current government.
Anything could happen in Thai politics, he added.
The Pheu Thai Party remained silent because it was cooperating and wanted the government to adhere to the reform roadmap that already had a set timeframe for a general election, Mr Worachai said.
The National Council for Peace and Order (NCPO) has said there could be a general election early next year, after a year of national reform following the May 22, 2014 coup.
Prime Minister and NCPO chief Prayut said on Tuesday that he was adhering to the roadmap and that authorities were working hard to solve national problems, including ensuring the makeup of the House of Representatives and the Senate would exclude a parliamentary dictatorship forming.
They were laying down national strategies to solve the problems, and the strategies would remain in place for the future government to follow, he said.