The opposition camp plans to lodge another petition against suspended Transport Minister Saksayam Chidchob with the Constitutional Court, asking that it revoke his right to contest the coming election.
Pakornwut Udomphiphatsakul, a list-MP of the Move Forward Party (MFP), said the opposition is gathering signatures of at least 40 MPs to back the planned petition, which will be submitted directly to the court.
On March 3, the Constitutional Court suspended Mr Saksayam, secretary-general of the Bhumjaithai Party, from duty pending its ruling on his alleged concealment of shares in a construction firm.
The suspension order was in response to an opposition petition filed with the court via the speaker of the House.
It alleged Mr Saksayam did not actually transfer his shares, which violated Section 187 of the charter and Section 4 (1) of a law governing the holding of shares by cabinet ministers. The opposition said that his cabinet status was terminated under Section 170 of the charter.
Mr Pakornwut said the new petition would ask the court to revoke Mr Saksayam's right to seek re-election because he might have violated Section 144 of the charter, which deals with examining budget expenditure.
Under Section 144, lawmakers are prohibited from increasing the annual budget expenditure bill. All they are permitted to do is trim the budget amounts during the scrutiny stage.
"The House is no longer in session, and the MPs are in their constituencies. We are trying to get the required signatures before the House dissolution. The petition will be lodged directly with the court," the MFP MP said.
In late January, the opposition initiated a petition to revoke Mr Saksayam's election rights and submitted it to the court via the House speaker under Section 82 of the charter.
However, the Office of the House Secretariat sent it back. It said the petition did not meet the criteria for the House speaker to process and recommended that the opposition submit the petition directly to the court.
Bhumjathai list-MP Supachai Jaisamut said on Sunday that the allegation against Mr Saksayam involved shareholding, so the court case against him had something to do with his cabinet status, not with the Bhumjaithai Party.
"Those trying to say the case is about corruption or linking it with the party are telling a lie," he said.