Bhumjaithai Party leader Anutin Charnvirakul.

The idea of setting up a "third" alliance is gathering steam with Bhumjaithai Party leader Anutin Charnvirakul touted as a surprise contender to become prime minister.

The move is seen as a bid to draw Bhumjaithai away from an alliance led by the Palang Pracharath Party (PPRP) which now seems to have an advantage over the Pheu Thai Party camp.

The Election Commission (EC) endorsed 99% of the 500 MPs last Wednesday.

Prachachat Party leader Wan Muhammad Nor Matha on Sunday vouched for Mr Anutin, saying the Bhumjaithai leader has what it takes to be the next prime minister.

"I want Mr Anutin to make a decision and not to rule out the chance. Serving as prime minister not only helps the country, but it is also the glory of your life,'' Mr Wan Nor said, adding that former Democrat Party leader Abhisit Vejjajiva is also suited to the role.

Prachachat, which won six constituency seats in the South and a party-list seat, is among six parties that have pledged allegiance to Pheu Thai in the wake of the March 24 poll.

Mr Wan Nor reaffirmed the party's intention of keeping the regime from prolonging its hold on power.

Commenting on reports the PPRP was pushing to form a coalition government comprising up to 20 parties, including small parties which were given one party-list seat each, Mr Wan Nor said that such a multi-party government is messy.

The PPRP has not yet made any official announcements, Mr Wan Nor said, adding that things will become clear after parliament convenes for the first time later this month.

Adul Khiawboriboon, chairman of a support group for relatives of victims of the 1992 Black May unrest, said on Sunday he agreed with the idea to set up a third alliance of parties.

He also voiced support for Mr Anutin to become the next prime minister.

But if Mr Anutin refuses, Mr Abhisit would be a good choice too, even though he resigned as Democrat leader, Mr Adul said, adding the next prime minister should not be Gen Prayut.

Mr Adul said that the primary aim of the proposed third alliance is to set up a government of national unity to break the deadlock as a result of rivalry between the two opposing camps, Pheu Thai and PPRP, rather than a way of adding leverage to deals for potential cabinet seats. He also said Gen Prayut should wash his hands of politics for the greater good of the country.

Reports were unclear on Sunday what policies the alliance would stand for, or who has joined up so far.

Pichai Naripthaphan, a former energy minister for Pheu Thai, threw his support for Mr Anutin to be the next prime minister on Sunday.

Mr Pichai, a former member of the now-dissolved Thai Raksa Chart Party, said Mr Anutin should keep his election pledge that he would not back Gen Prayut's return to power.

"If Mr Anutin and Bhumjaithai keep their promise, the party is likely to grow further and Mr Anutin will also stand a big chance of becoming prime minister,'' he said.

Khunying Sudarat Keyuraphan, chief of Pheu Thai's election strategy panel, said the party had not yet discussed any bid to promote Mr Anutin.

She added Pheu Thai was waiting to see whether the Democrats and Bhumajaithai would decide to join the Pheu Thai-led alliance.

Ongart Klampaiboon, a Democrat party-list MP, said the party's direction will become clear after May 15 when a new executive board and party leader are chosen.

The Pheu Thai-led alliance's hopes of forming a coalition government took a blow after the EC endorsed 149 party-list MPs and also approved all 349 constituency MPs with a formula that rewarded parties likely to support the military.

The poll agency's decision to award one party-list seat to 12 small parties effectively reduced the number of seats garnered by the Pheu Thai-led bloc to 245, while the PPRP-led alliance is now expected to muster 253 seats.