Final pleas for life of Briton on death row in China
Mr Lewis said he hoped the UK's relationship with China would count for something
The UK government has made a final appeal to China to halt the execution of a 53-year-old British man who is thought to be mentally ill.
Foreign Office minister Ivan Lewis said the execution would be "entirely inappropriate" after the talks.
Akmal Shaikh, of London, was reportedly told by his family that he faced death at 1030 (0230 GMT). It is not yet known if the sentence has been carried out.
He was convicted of drug smuggling, but has denied any wrongdoing.
The BBC understands that if the execution has gone ahead, the Chinese authorities will inform the British authorities at a senior level, and the British authorities will first let Mr Shaikh's family know and then the media.
Just before the execution deadline, Mr Shaikh's two cousins who visited him on Monday issued a statement at Beijing Airport repeating calls for leniency because of his mental state.
But at the same time an official statement from the Xinhua news agency reiterated a Supreme Court ruling that the evidence that Mr Shaikh suffers from mental illness was "insufficient".
Mr Lewis held last-ditch talks with the Chinese ambassador in London on Monday evening.
The minister said after the talks: "We hope that the relationship we have with China will count for something in the end.
"It's entirely inappropriate that he be put to death. We've made 27 representations over the last two years and even at this late stage I hope they will see that in a modern world it is not appropriate to put a man with mental illness to death.
"It cannot be right that there has not been any medical assessment done of Mr Shaikh's mental condition. In any judicial system that simply cannot be acceptable."
Mr Lewis added: "I believe this meeting tonight was the final opportunity for us to make the strength of our feeling known to the Chinese. I believe we have done everything we possibly can."
Mr Shaikh has denied all knowledge of the 4kg of heroin found in his possession by police in the north-western city of Urumqi in 2007.
His family say he suffers from bipolar disorder and has displayed "extreme and erratic" behaviour.
His daughter Leilla Hornsell told the BBC: "I don't think he will be able to really understand what's happening."
Ms Horsnell has said her father was approached by drug smugglers in Poland who convinced him they would make him a pop star in China.
She claims he was then duped by the gang into carrying a suitcase that did not belong to him.
The last-minute nature of this evidence is an example of why there must always be last-minute clemency
"I'd like to be hopeful, but time just seems to be running out," she said.
"It's better for him to be in his own world rather than be faced with the reality of the situation."
Mr Shaikh's final appeal was turned down last week. He is set to become the first EU national to be executed in China in 50 years.
His cousins, Soohail and Nasir Shaikh, informed him of his fate as they spent an hour and a half with him on Monday at the secure hospital in Urumqi where he is being held.
They were the first family members to have face-to-face contact with him in two years.
His cousins also handed in a petition to the local court asking for a stay of execution and made a plea for mercy to Chinese President Hu Jintao.
Song for peace
Legal charity Reprieve has been working on the case with Mr Shaikh's family.
The organisation has collected witness statements from people who knew Mr Shaikh while he was sleeping rough in Poland.
CHINA DEATH PENALTY
China executed 1,718 people in 2008, according to Amnesty International
Last year 72% of the world's total executions took place in China, the charity estimates
It applies to 60 offences, including non-violent crimes such as tax fraud and embezzlement
Those sentenced to death are usually shot, but some provinces are introducing lethal injections
The witnesses all say Mr Shaikh was clearly mentally disturbed and was fixated on recording a song that he believed would usher in world peace.
Reprieve's director Clive Stafford Smith said: "While it must be torture for Akmal going through this, the last-minute nature of this evidence is an example of why there must always be last-minute clemency."
A spokesman for the Chinese embassy in London said Mr Shaikh was found with enough heroin to kill 26,800 people.
"Drug trafficking is a grave crime worldwide," he said.
"The general public has a deep-seated hatred toward it."
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