A member of Mon Unity Party's (MUP) central executive committee (CEC) resigned after the political party joined the military regime's Mon State Administrative Council.
Dr Aung Naing Oo sent his resignation letter on Monday.
Aung Naing Oo and nine other CEC members asked the Mon political party to reconsider joining the council, which the military quickly assembled after staging a coup on February 1.
"We want to choose the democratic path. But now that there's a disagreement between my party's policy and my own position it's better to walk away,” he said.
"I don't want to be an unjust person. I won't deviate from democratic values and normality because I respect voters,” he wrote on his Facebook page. “I want an elected civilian government and a democratic administration. Down with the dictatorship!"
On February 6, most of MUP's senior members decided to join the military regime's council.
According to Myanmar Radio and Television, Nai Layae Tama, MUP joint secretary 1, was sworn in a day before Aung Naing Oo resigned from the party.
Many criticized MUP for accepting the military government.
Nai Layae Tama explained joining Mon State Administrative Council was about choosing a path that allows for negotiation and dialogue rather than confrontation.
Aung Naing Oo was elected as a parliamentarian for Chaung Sone Township during the 2010, 2015 and 2020 races. From 2015 to 2020, he served as the deputy parliamentary speaker for Mon State
