The Nida poll director has vowed to quit after a poll he conducted relating to Deputy Prime Minister Prawit Wongsuwon's luxury watch scandal was suppressed.

Many observers think the government put pressure on the institute, persuading its rector to step in and prevent the poll from being published.

Social media lit up on Sunday with criticism of the government for interfering, forcing its spokesman to deny the claim.

According to a source, the poll indicates that up to 85% of respondents do not believe Gen Prawit's explanation that his luxury watches were borrowed from friends. This damning statistic threatens to further undermine public confidence in the way the government has handled the scandal.

"Although I support the coup and government, if [I see] that something isn't right or just, I don't have to 'lick top boot,'" said poll director Arnond Sakworawich in a message posted on Facebook on Sunday, explaining his decision to resign. He had been in the job just two weeks, working on three polls in that time.

Mr Arnond said that, as an academic, he has to present the facts plainly, and he would never betray that principle or the people. He stressed that a person holding a management post in any academic institution must pursue academic freedom and show ethical courage.

"If I can't maintain these things, there's no reason for me to stay in the office," he said.

He and his team tried to conduct the poll with academic integrity and present the information accurately and carefully. 

"But then one of the staff at Nida told me the rector had ordered any politically-related poll to be reviewed by him and that he ordered a halt to this poll," he said.

"I think [the rector] is afraid, but I'm not. I respect him, as he was my teacher. But academically, I have the right to be myself."

The suppression of this latest poll came after the results of another survey were published showing that the majority of respondents doubt the transparency of the National Council for Peace and Order (NCPO).

It showed that 76.3% of respondents thought there were "irregularities" in the NCPO led by Prime Minister Prayut Chan-o-cha and in his government itself, while only 16.64% had confidence in its transparency. The other 7.04% declined to answer.

About half of respondents doubted the willingness of the National Anti-Corruption Commission (NACC) to conduct a genuine investigation into such high-ranking politicians as Gen Prawit.

Pheu Thai Party legal adviser Ruangkrai Leekijwattana said he suspected influential figures had interfered in the recent poll's suppression as they could see the government's popularity declining, particularly due to the watch scandal.

Government spokesman Lt Gen Sansern Kaewkamnerd denied the government had tried to block the poll results and insisted it was not trying to curb academic freedom.

Mr Arnond's resignation should not be linked to the government and the deputy prime minister's watches, he added.

Meanwhile, Nida president Pradit Wanarat said he is the person accountable for the decision to halt the poll. Since the case of Gen Prawit is still being investigated by the NACC, the poll results might influence public opinion.

The rector also stressed that Nida Poll has always tried to uphold academic freedom, adding that once Gen Prawit's case reaches completion, the committee will review the poll again. He would discuss the matter with Mr Arnond today.