An armed group demanded that Britain leave Iraq in video footage aired by the Dubai-based al-Arabiya news channel on Tuesday, which showed one of five Britons seized in May.
"I have been here, now held for 173 days, and I feel we have been forgotten," a man identifying himself as Jason said in the video.
A British management consultant and his four bodyguards, whose names have not been released to protect their safety, were abducted during a visit to an Iraqi Finance Ministry office in Baghdad on May 29.
In June, General David Petraeus, the top commander of United States forces in Iraq, said in an interview with the Times newspaper in Britain that the hostages were kidnapped by a group funded, trained and armed by Iran.
He added that there had been repeated attempts to free them and identified the kidnappers as a secret cell of the Mahdi Army, the Shi’ite militia loyal to radical cleric Moqtada al-Sadr, who in September ordered the suspension of its armed activities.