The Pheu Thai, Bhumjaithai and Palang Pracharath parties could form a coalition government if they capture more than 251 House seats in the next general election, Senator Wanchai Sornsiri said on Tuesday.
Mr Wanchai said PPRP leader Gen Prawit Wongsuwon could work with any political camp, so it was possible his party might join hands with Bhumjaithai and Pheu Thai after the election.
"The prime minister could come from parties other than the PPRP and Pheu Thai. Don't underestimate Bhumjaithai. If the current government can't muster enough House seats, they might have to compromise.
"Pheu Thai's [prime ministerial candidates] could create conflicts, and the party may have to compromise with Bhumjaithai and the PPRP," said Mr Wanchai.
He said the political situation has changed and much of the Senate is likely to vote for the prime minister nominated by a bloc commanding a majority in the House.
The bloc that supports Prime Minister Prayut Chan-o-cha must gather at least 251 House seats to secure his return as prime minister, Mr Wanchai said, adding he was unsure if the situation would work in Gen Prayut's favour.
On a proposal to amend the charter to remove the eight-year term limit, he said the issue was still being studied along with others by the Senate committee on political development and public participation.
However, he stressed that if the House did not support the proposal, it would never materialise.
Senator Kittisak Rattanavaraha, a member of the committee, said the proposed removal of the prime minister's term limit would be submitted only when MPs or the public initiated a fresh effort to have the charter amended.
"In the next government, if there is an attempt to revise the charter, the Senate will submit its charter amendment proposal, which includes a term limit among its proposals. We'll also call for a referendum," he said.
Mr Kittisak echoed Mr Wanchai's opinions that the Senate is unlikely to vote for the prime ministerial candidate nominated by the minority in the House.
Pheu Thai member Chaturon Chaisang slammed the Senate, saying senators should decrease their role in politics to ensure people's votes are not distorted.
