Labour Party of Kenya leader Ababu Namwamba has relinquished his position in the party so he can focus on his new role of Chief Administrative Secretary in the Ministry of Foreign Affairs.
The former Budalang'i lawmaker was last month appointed CAS by President Uhuru Kenyatta.
"My appointment puts me in a place where I have to relinquish my political party post under Article 131 section 4 A on presidential appointments so that I can serve Kenyans," said Mr Namwamba.
Addressing party officials on Saturday at Noble Hotel in Eldoret Town, Mr Namwamba said he would continue offering his support to the Labour Party ahead of the 2022 General Election.
"Even as I exit the scene, I want to assure all of you that I am committed to continue offering my support to you and I have a lot of confidence in the team that I am leaving behind," added Mr Namwamba.
The event was also attended by the party Chairperson Julia Ojiambo and Deputy Party Leader Esther Kondo.
Mr Namwamba has served as party leader since September 2016 when the party relaunched.
He lauded foreign envoys for maintaining that President Uhuru Kenyatta was duly elected.
"I want to laud the foreign envoys who have been calling for the closure of the last elections and maintaining that the country needs to focus on its development agenda. These are true friends of Kenya," said Mr Namwamba.
He pledged to execute his mandate in accordance with the law.
"The Ministry of Foreign Affairs is the window in which the world sees us. I will work with all the concerned parties in ensuring that we achieve our vision as a country," he said.
In the run-up to the August 8 General Election, Mr Namwamba was a fierce critic of Mr Kenyatta's administration before falling out with leader in ODM - where he was the Secretary General.
Mr Namwamba then ditched ODM to run for MP on the Labour Party of Kenya ticket.
Having severed his relationship with the Opposition, he transformed himself into a harsh critic of ODM leader Raila Odinga and a staunch supporter of President Kenyatta.
Mr Namwamba was defeated by Mr Raphael Wanjala in the Budalang'i MP contest.