Their kidnappers have threatened to kill them unless their demands are met by Thursday – with time running out, Western aid workers seized in Iraq have made pleas for their lives.Briton Norman Kember urged Prime Minister Tony Blair to take British troops out of Iraq in a video tape aired on the Arabic television channel Al Jazeera. Meanwhile, a jailed Jordanian cleric has called for the mens’ release. Abu Qatada is being held in the UK, where he has been accused of links with al Qaeda. Two Canadians and American Tom Fox are also being held by the kidnappers who want Iraqi detainees in the country to be freed. Fox’s daughter Katherine went on US television to urge the kidnappers not to carry out the death threat. “The work that he is there to do is the same work that they would like to see done and I do not think a loss of his life benefits their cause,” she said. German Susanne Osthoff is also facing a death threat. The archaeologist and aid worker was seized with her driver almost two weeks ago. Former German Chancellor Gerhard Schroeder appealed for their release in a recording aired on Al Jazeera. Osthoff’s kidnappers want Berlin to end all co-operation with the US-backed Iraqi government. Germany does not have troops in Iraq but helps train its forces outside the country.