The mother of a girl kidnapped by Boko Haram has issued a plea to the Prime Minister to help rescue her daughter ahead of the anniversary of her abduction.
On 19th February 2018, Leah Sharibu was taken from her school in Dapchi, north-eastern Nigeria, along with 109 of her classmates.
Now aged 16, Leah is thought to be the only one of the class still held by the extremist militants because she refused to convert from Christianity to Islam.
Marking the two-year anniversary of her kidnapping at an event in Westminster, Leah's mother Rebecca Sharibu said she was "constantly in pain" over her daughter's abduction.
Speaking Hausa translated by Dr Gloria Puldu, the head of the foundation set up in the 16-year-old's name, Ms Sharibu asked for the British Government to ask Nigerian President Muhammadu Buhari to intervene in her case.
Ms Sharibu told the PA news agency: "I have come to plead with the UK, the US, all the nations to please hear me and help me out.
"I am pleading with your Government, please do whatever you can to get my daughter Leah released.
"I want to plead directly to Boris Johnson that he should please help me and President Buhari to release my daughter.
"Tomorrow my daughter, my only daughter, will be two years in captivity, and (President Buhari) has promised me that she would be released but she has not been released."
Linked to the so-called Islamic State terror group, Boko Haram are known for mass abductions of schoolgirls and attacks in north-eastern Nigeria, Chad, Cameroon and Niger.
Just over a month after the abduction, 104 of Leah's classmates were released and five girls had died.
Ms Sharibu, who travelled from Nigeria to the UK on Monday, asked for the Nigerian president to intervene as he and the government had in March 2018.
She continued: "I need Leah back home and I need him to set Leah free, just like the other girls were set free.
"The students who were taken along with Leah have been brought back to their parents and their parents do not know the pain we have been going through for two years, pains that cannot be described. So please, help us."
Boko Haram prompted an international outcry after the 2014 attack on a boarding school in Chibok, where militants kidnapped 276 girls, some of whom are still being held by the group.
Ms Sharibu said she had only heard "rumours" about her daughter's condition in captivity, but believed she was still alive as a healthcare worker who had been released reported hearing Leah was alive from another captive.
She said: "On a daily basis we hear Leah this, Leah that. We are in great pains.
"At times, when the stories come out, we feel so pained, we feel so terrible. So if I tell you that I am happy, I am telling you a lie. We are constantly in pain, all we desire is to have Leah back with us."
Baroness Caroline Cox also spoke at the event to help launch the International Organisation for Peace and Social Justice's Silent Slaughter campaign to raise awareness of violence in Nigeria.
Baroness Cox spoke about persecution of Christians by Islamist extremists, some of whom are part of the Fulani ethnic group.
Warning about the risk of a genocide, she told PA: "The British Government ought to recognise the seriousness of what's happening.
"What has been happening is absolutely unacceptable.
"But it's getting to be part of a bigger picture of it, ethnic and religious cleansing, supported by an interconnection of different Islamist militant groups, and that is a very serious agenda."