The Bhumjaithai Party (BJT) has authorised its candidates to file a complaint with the poll watchdog against Srettha Thavisin.
Mr Srettha, who is a prime ministerial candidate and executive board member of the Pheu Thai Party, discredited the BJT, in violation of election laws, the party says. It has urged members to complain to the Election Commission (EC).
If the EC finds against him, it could impose the maximum penalty of urging Pheu Thai to be dissolved.
Supachai Jaisamut, registrar of the BJT party, said at least 10 of its candidates will file a petition with the EC in their respective provinces. The petition asks the commission to investigate Mr Srettha and the executive board. It alleges Mr Srettha's remarks at a recent campaign rally were misleading.
He said Mr Srettha, during election campaigns, told audiences that BJT had a policy for complete and total liberalisation of cannabis, which has led to misuse of the drug among adolescents. "This is false," Mr Supachai said.
Mr Supachai argues the Public Health Ministry, under the direction of BJT, has issued regulations to prevent improper use of cannabis, including bans on public consumption and use by children.
Mr Supachai also said Mr Srettha falsely claimed that voting for BJT would result in Gen Prayut Chan-o-cha becoming prime minister again. That's untrue, as Anutin Charnvirakul, BJT's party leader, has consistently said he wants to be prime minister.
"We have never criticised another party, especially those that have not identified proper funding for their policies that could result in significant financial burdens for the country," he said. "Mr Srettha is not mature enough for politics."
Asked what this would mean for a possible BJT-Pheu Thai coalition, he said Mr Srettha is just an opportunist vying for the role of PM.
"If Mr Srettha fails, he will just go back to selling houses."
