Members of Parliament affiliated with the ODM party have asked President Uhuru Kenyatta to remove Defence Cabinet Secretary Raychelle Omamo from the position, saying she is not inspiring enough to soldiers serving under her.
They said she has appeared aloof and unable to inspire soldiers and should therefore be replaced by someone else.
They also asked the government to withdraw Kenyan forces from the war-torn country, saying the strategy aimed at wiping out Al-Shabaab had failed.
Rarieda MP Nicolas Gumbo said having Ms Omamo as a Defence CS was a "mistake". He said she is not fit for the position.
"She should be given lighter duties. She is the wrong person for the Ministry of Defence. She should be given other lighter duties. She looks more like a nun … than a Defence CS. She is not inspiring at all," said Mr Gumbo.
Suna East lawmaker Junet Mohamed said although he came from the same region as Ms Omamo, he and his fellow MPs were no longer supporting her, adding that she was not competent to lead the country against an enemy.
"The last job she should perform is to be the chair of the burial committee of the killed soldiers. This is the worst-performing minister this country has ever had since independence," said Mr Mohamed.
The MPs, who said they were speaking on behalf of ODM, said they would consider impeaching her if she is not removed soon.
Other MPs who addressed reporters at Parliament were Kitutu Masaba MP Timothy Bosire and Balambala MP Abdikadir Aden.
They also urged the government to tell the country the exact number of soldiers killed in El-Adde, Somalia, last Friday and contact their families as soon as possible.