Akmal Shaikh was arrested in north west China in 2007
A campaign to halt the execution of a British man in China has been launched by the human rights charity Amnesty International UK.
Akmal Shaikh, 53, from Kentish Town, north London, faces the death penalty for drug smuggling after he was found with heroin at China's Urumqi Airport.
The father-of-three's supporters say he is mentally ill and had been tricked.
Amnesty is urging people to write to China's Supreme Court asking it to stop the planned execution.
According to his family, Mr Shaikh, who is married, has bipolar disorder.
He travelled to China in 2007 with the promise of being made into a pop star, despite having no singing experience, they said.
Actor Stephen Fry, who also suffers from bipolar disorder, last week appealed to the Chinese government, describing Mr Shaikh as "very delusional" and asking for clemency in this "real case for mercy".
Amnesty said on Wednesday Mr Shaikh had lost his final appeal and now faced execution.
The organisation said Chinese authorities had refused to allow a doctor to carry out a psychological assessment of him despite having provision within their laws to spare people suffering from mental illness the death penalty.
Campaigns director at Amnesty UK Tim Hancock said: "China's Supreme People's Court has it in their power to stop this execution.
"We're calling on people to write to them immediately, urging them to intervene."
Executive director of legal charity Reprieve Clare Algar said: "Sadly, our investigations show that Akmal Shaikh is on death row because he is mentally ill.
"Thankfully, there is a mental illness defence in China. We hope that Amnesty's urgent action will encourage the Supreme People's Court to consider it and spare Akmal's life."
The Foreign Office said last week that the prime minister had raised the case with China's leadership "several times".