Lawyers acting for Mohammed Asghar, a British citizen suffering from severe mental illness filed an appeal on Friday against his conviction and death sentence for blasphemy in the Islamabad High Court. A statement from Reprieve, the legal charity which is helping him, said the appeal challenges Asghar's conviction on a number of grounds, including the court's failure to consider any evidence of Mr. Asghar's mental health problems, which are detailed extensively in the National Health Service records from the UK.

Mr. Asghar's lawyers say that the appeal may take up to five years to be heard by the High Court, owing to a huge backlog of cases. The statement said having visited Mr. Asghar yesterday, the lawyers fear that his poor health means he is ill-equipped for a lengthy wait. Mr. Asghar remains severely mentally-ill, they report, but the prison authorities have not yet taken the necessary steps to provide him with the specialist medical treatment he urgently requires.

Mr. Asghar's case this week attracted attention from Westminster and the Scottish Parliament in Edinburgh. Speaking at Prime Minister's Questions on Wednesday, David Cameron said he was "deeply concerned", and that "the Pakistani authorities can be in no doubt of the seriousness with which we take these developments."

Meanwhile, a motion tabled in the Scottish Parliament calling on the Pakistani authorities urgently to review Mr. Asghar's case has received cross-party support.

Maya Foa, Director of Reprieve's death penalty team, said in the statement, "We have grave concerns about the ongoing lack of appropriate medical treatment for Mr. Asghar, and hope that the British and Pakistani Governments will do everything they can to ensure that he receives treatment without further delay. I trust that both governments are exploring every possible option to ensure that it does not take five years to see the effects of this terrible miscarriage of justice reversed."