Senator Teerakiat Jareonsettasin has decided to resign his seat and leave politics after the Constitutional Court found a conflict of interest with his wife's shareholdings.
Dr Teerakiat said he sent his resignation letter to Senate Speaker Pornpetch Wichitcholchai on Wednesday morning.
Although the Constitutional Court's ruling on Tuesday related only his past ministerial position, he preferred to end the matter quickly, and the senate speaker accepted his decision, Dr Teerakiat said. He was education minister in the previous Prayut government.
His resignation would take effect this Friday, he said.
Dr Teerakiat said he would not return the remuneration he had received as a senator because he resigned and had not done anything wrong while holding the seat.
He declined to comment further on whether the Constitutional Court's ruling would affect his senate position.
Regarding his wife's shareholdings, he said his wife had no idea she had done anything wrong, but ignorance could not be raised as an excuse.
Dr Teerakiat said that with his resignation from the senate he would also end his involvement in politics. He'd had enough of it.
His resignation will promote Apichart Todilokwet into the senate. He is second on the waiting list after Don Pramudwinai, who cannot become a senator because he is already the foreign minister.
On Tuesday the Constitutional Court found Mr Teerakiat's wife had bought 800 shares in state concessionaire Siam Cement Group (SCC) Plc after his appointment to the cabinet. The couple owned 4,200 SCC shares prior to Dr Teerakiat taking up the education portfolio in the previous government.