The Move Forward Party (MFP) called for the prime minister to reconsider the recent appointment of Education Minister Pol Gen Permpoon Chidchob due to allegations he helped Vorayuth "Boss" Yoovidhya, the scion of the family behind the Red Bull empire, escape prosecution.
At the press briefing on Friday, MFP MP Teerajchai Phunthumas spoke about the National Anti-Corruption Commission (NACC) decision to formally accuse a number of people it found were involved in mishandling the infamous 2012 hit-and-run case by Mr Vorayuth.
One of them is Pol Gen Permpoon, who was an assistant to the then-national police chief Pol Gen Somyot Poompunmuang.
In the early hours of Sept 3, 2012, Mr Vorayuth crashed his Ferrari into a motorcycle driven by Pol Snr Sgt Maj Wichian Klanprasert in the Thong Lor neighbourhood.
Instead of stopping to help the victim, Mr Vorayuth, then in his early 20s, drove off, dragging the victim's body 200 metres from the accident scene. He did not report it.
After repeatedly ignoring orders to appear in court, he fled the country in 2017.
The statute of limitations on some charges has already expired.
Mr Teerajchai said Pol Gen Permpoon had altered the official speed estimate to below the safety threshold and had reassigned police officers who wanted to request a red arrest warrant, leading to the court dismissal and Mr Vorayuth's escape to London.
Even though the punishment given to Pol Gen Permpoon is a disciplinary one, Mr Teerajchai noted that Srettha Thavisin is both the prime minister and president of the Police Commission.
He will be expected to consider the suitability of Pol Gen Permpoon for the education portfolio.
"People question the fairness of the justice system with regard to the rich and poor. In this case, some people have been offered assistance to flee the country and escape prosecution to this day," said Mr Teerajchai.
He added the NACC's report had confirmed the names of people involved in the hit-and-run case, so the government should assign another investigation to prosecute more accomplices as well as to repatriate Mr Vorayuth to face his punishment.
"The Royal Thai Police can send a notice to European police to apprehend Mr Vorayuth using his biometrics to identify him, an order which can be made by the ruling government.
"But I doubt that Mr Srettha will proceed to bring this case out of the dark because Pol Gen Permpoon is a Bhumjaithai Party MP, and those seats are important to the coalition," said Mr Teerajchai.
Meanwhile, Mr Srettha told the press he has not read the report yet.