Foreign secretary Jack Straw has repeated his call for Iraqi militants to release four Westerners they are holding hostage.
And although he has insisted there will be no negotiations with terrorists, Mr Straw called on the kidnappers to "get in touch", saying: "We want to hear what they have to say."
This morning, it has been reported on Arabic TV channel al-Jazeera that the deadline for executing the hostages, who include Briton Norman Kember, two Canadians and an American, has been extended from today to Saturday.
Mr Straw's comments last night came just hours after British-held Jordanian prisoner and suspected al-Qaeda member Abu Qatada made an apparently voluntary televised plea to release the Christian activists.
"I beseech my brothers in Swords of Truth in Iraq, to release them in accordance with the fundamental principle of mercy of our faith, if there is no compelling religious duty against it," the cleric said.
Mr Kember, 74, has previously appealed to Tony Blair to withdraw British troops from Iraq and to allow the Iraqi people to come to their own decisions.
The four hostages, who work for non-governmental organisation Christian Peacemaker Teams, were seized in Baghdad last month, accused of spying for foreign forces in Iraq.
In a statement released last night, Mr Straw said: "Our overall position in respect of kidnapping has been made very clear already.
"These four men are all campaigners for peace, dedicated to the helping of others, and we ask for their release."
He added: "If the kidnappers want to get in touch, we want to hear what they have to say."