British Prime Minister Mr Tony Blair says he is ready to open up contact with the captors of Mr Kenneth Bigley in Iraq.
Mr Bigley (62) was shown on video chained and squatting in a cage, pleading to Mr Blair for help while accusing him of lying over the hostage crisis.
"They've made no attempt to have any contact with us at all. If they did make contact, it would be something we would immediately respond to," Mr Blair told reporters on the fringes of his Labour Party's annual conference in Brighton.
"I don't think we can take any hope from anything until we know exactly what the intentions of these people are," Mr Blair said. "They're not in contact with us, it's impossible for us to make contact with them."
Mr Blair has said repeatedly he will not negotiate with the kidnappers, who demand release of women prisoners held in Iraq.
Al Jazeera television broadcast a tape showing a distraught Mr Bigley dressed in an orange jumpsuit of the kind associated with Muslims held by US troops at Guantanamo Bay.
"Tony Blair is a liar. He doesn't care about me. I'm just one person," Mr Bigley said, his voice cracking under the strain.
Mr Bigley's two American colleagues, seized with him from their house in Baghdad two weeks ago, have already been beheaded on video by a group led by Jordanian al-Qaeda ally Abu Musab al-Zarqawi.
The latest tape of Mr Bigley was aired a day after the two Italian women and four Egyptian engineers were freed.
Italy reacted with joy to the release of Simona Pari and Simona Torretta, who spoke of returning to Iraq despite their three-week kidnap ordeal.
But there was controversy over reports Rome paid a $1 million ransom to win the women's freedom - the kind of response Iraqi officials said would promote kidnappings.