Chaikasem Nitisiri, Pheu Thai Party's chief strategist, said on Thursday that any of the party's three prime ministerial candidates could be nominated for the top job.
The other candidates, apart from Mr Chaikasem, are Paetongtarn Shinawatra and Srettha Thavisin.
The party's board will decide who eventually gets the nod, rather than following the numerical order assigned to these three figures when its list was submitted to the Election Commission (EC) on Wednesday, he said.
Yet he claimed he had not been informed his name was on the list until the party asked him to fill in a form for submission to the EC that day.
Mr Chaikasem refused to confirm speculation that Mr Srettha -- who was already describing himself on Wednesday as "Thailand's next prime minister" -- will eventually be nominated as Pheu Thai's prime ministerial candidate.
"It could be any of the three," he said. "In principle, the one most capable of handling the country's problems will represent the party."
Empty promise
Piyabutr Saengkanokkul, a key figure of the Progressive Movement who is assisting the Move Forward Party (MFP) in its election campaigning, has called Pheu Thai's pledge to make up for the harm inflicted by the previous military coup as an empty promise.
He denounced the claim in posts on both Twitter and Facebook, saying the party has had several chances to make good on its promises, but history suggests it is all talk.
"Honestly! Stop bragging. That's so annoying. You were a government with a majority voice in the House before; but no such thing has been done as [you] promised so far," he wrote on one social media platform.
After former premier Thaksin Shinawatra was ousted in the Sept 19, 2006 coup, Pheu Thai -- then known as the People Power Party -- won the election in 2007. However, it did not attempt to amend the constitution until two years later when it faced massive anti-government protests, said Mr Piyabutr.
Pheu Thai won the election again in 2011 but the Yingluck Shinawatra administration also failed to amend the charter and instead pushed for a blanket amnesty law to be passed, which eventually resulted in yet another coup on May 22, 2014, he said.
Fierce contest
The House seats in the capital will be very hotly contested, more so than in the 2019 elections, and the outcome isn't likely to be evident until the very last minute, said core Palang Pracharath Party member Narumon Pinyosinwat.
"Anything is possible. [Bangkok] residents are ready to give other candidates a chance, as they no longer vote along party lines," she said. "They look at the party's prime ministerial candidates and stance on current affairs. It's hard to predict."
That said, she said the PPRP is hoping to retain at least the 12 seats it won in the previous election.
In an effort to reach that goal, the party has fielded its best candidates to defend its turf in the capital and hopefully expand its supporter base from 790,000 to about one million, she said.
Ms Narumon said one of the PPRP's priorities for Bangkok is ensuring housing security, as many residents do not own their homes. The party will take into consideration the country's fiscal situation when pushing social welfare schemes, she added.
End draft for economy
Meanwhile, one of the highlights of the Move Forward Party's recent campaign is its pledge to abolish mandatory conscription. To hammer home its message, its candidates and key figures recently dropped by an auditorium where the annual conscription formalities were underway.
MFP candidate Songpol Pattrapirom, who is vying for a seat in Chai Nat's Constituency 1, told people at the auditorium that the party will abolish the draft if it comes to power.
Pannika Wanich, a co-founder of the now-defunct Future Forward Party who works as the party's campaign assistant, said that ending conscription would free more people up to return to the labour market, thus helping drive the economic recovery.
She said conscription should be replaced with voluntary enlistment, adding the MFP's military reforms will include downsizing the armed forces by 30-40%, reducing the number of generals to 400 and increasing welfare benefits for low-ranking officers.
As of last year, there were 771 active generals in the three Thai armed forces.