The Prince and Duchess will meet Pakistan President Musharraf
Prime Minister Tony Blair says he has spoken personally to Pakistan's president to ask him to intervene in the case of a Leeds man on death row.
Mirza Tahir Hussain, 36, is due to be executed on 1 November for murdering a taxi driver in 1988.
Prince Charles later said he had spoken to Pakistan's prime minister, Shaukat Aziz, with his concerns over the case.
His involvement emerged after he was urged to cancel a visit to the country which will coincide with the execution.
Mr Blair said he had raised the matter personally with President Pervez Musharraf when he visited the UK.
He declined to comment on the planned royal visit, but said he hoped "even at this stage" there was an intervention to stop the execution.
He said: "There is a limit to what the president can do but I hope he can use the powers that he has and we will continue to make representations right up until the last moment."
Prince Charles and the Duchess of Cornwall are due to meet President Musharraf during their planned visit to the country from 29 October to 3 November.
A spokesman for the Prince said: "The Prince of Wales has been concerned about this case for some time and had raised it with the prime minister for Pakistan."
The spokesman said he could not confirm when the conversation had taken place.
Leeds MP Greg Mulholland said it would be "monstrous" for Mr Hussain to be hanged during the Prince's visit.
Mirza Tahir Hussain said he acted in self-defence
He has written an urgent letter to the Prince asking him not to go ahead with the visit unless the execution is cancelled.
He said: "For this unjust execution to go ahead anyway would be bad enough, but to do this when Prince Charles, heir to the British throne, is visiting the country would be monstrous.
"Cancelling the visit will send a clear and powerful message to the Pakistani authorities."
Mr Hussain's case has won the backing of UK and Euro MPs and Amnesty International, who have all urged President Musharraf to quash the penalty.
Respect Party MP George Galloway had planned to fly to Pakistan on Monday to appeal directly to the president to quash the penalty, but cancelled the trip at the request of Mr Hussain's family.