A British member of parliament, Liberal Democrat MP Tom Brake launched a protest at Nigerian Nigerian embassy in London, to demand the release of Leah Sharibu.
Leah was one of the 100 schoolgirls kidnapped in Dapchi, Yobe State, by Boko Haram. But she was held back when others were released because she refused to renounce her Christian faith.
"The girls that returned said Leah said she will not deny Christ or turn to be a Muslim," Leah's father, Nathan said in an Interview.
Reno Omokri, former Special Assistant to President Goodluck Jonathan, on Thursday joined Brake in his protest.
The protest which started on Tuesday was organized by advocacy group Church World Service and will last 200 hours as Thursday marks 200 days since Sharibu, who turned 15 in captivity, was taken.
Organizers said members of the advocacy group will take turns to seat at a school desk placed in front of the commission's office with Sharibu's portrait.
Speaking in London, Omokri encouraged the Nigerian government to negotiate her release.
Noting that the insurgent group had released an audio to show that she is alive, Brake urged President Muhammadu Buhari not to use the kidnap of Leah to score cheap political points.
"There cannot be a clearer example of someone whose human rights are being ignored than that of Leah who is being detained just because she has maintained her Christian faith," Brake said in an email interview with CNN.
President Buhari's spokesman Garba Shehu a few weeks ago said that the president would "not rest until Sharibu and other girls in the group's captivity are reunited with their parents.
"For President Buhari, nothing will be spared in bringing all our girls home. He will not rest until all of them are free," Shehu said.