A British opposition politician is calling on the U.K. government to investigate allegations of human rights abuses against Biafran independence protesters in Nigeria.

Thousands of people have demonstrated across southeast Nigeria in recent months, calling for a referendum on independence for the former Republic of Biafra, which existed between 1967 and 1970 and was mainly populated by members of the Igbo ethnic group. Nnamdi Kanu, the leader of a prominent pro-Biafra group called the Indigenous People of Biafra (IPOB), was arrested by Nigerian security forces in October 2015 and has been in detention since. Kanu is to stand trial in Nigeria on Monday charged with treason, which carries a maximum life sentence in Nigeria.

Angela Rayner, Shadow Minister for Work and Pensions and Labour MP for Ashton-under-Lyne in northwest England, tells Newsweek that she raised the issue with the Foreign and Commonwealth Office (FCO) after receiving evidence from constituents alleging human rights abuses against Kanu – who is a dual U.K-Nigerian national – and pro-Biafra protesters in Nigeria.

“There is a strong Biafran presence in my constituency and I’m concerned that we don’t sit on our morals,” says Rayner. “I expect the government to take the issue seriously and to ensure they do everything in their power to protect individuals across the world.”

Kanu’s group alleges that scores of their members have been killed during protests since October 2015 and Amnesty International told Newsweek earlier in February that it was investigating reports of abuses in at least four locations – Aba, Enugu and Onitsha in southeast Nigeria and Port Harcourt in southern Nigeria.

An FCO spokesperson told Newsweek: “The U.K. takes all accusations of human rights abuses seriously. We do not share the assessment that there is institutionalised persecution of the Igbo or any other peoples by the Nigerian authorities.” The spokesperson added that British consular officials had visited Kanu several times and that, on each occasion, the activist was in good health and said he had access to a doctor and his lawyer.

Rayner spoke to Newsweek ahead of a pro-Biafra demonstration held outside the Houses of Parliament in London on Wednesday, which she attended. A pro-Biafra demonstrator attending the event told Newsweek that around 150 people had gathered with Biafran flags to demonstrate.

•Text courtesy of Newsweek. Photo shows British PM David Cameron.