Emotional pleas are the only weapon left for Bigleys

In the end, the strain of her son's ordeal took its toll on 86-year-old Elizabeth Bigley. A day after the grainy 11-minute video of Kenneth Bigley pleading for his life was released by his captors to a global internet audience, and with little indication as to whether he was still alive, Mrs Bigley collapsed at her Liverpool home and was taken to hospital on a stretcher.

The family had been pleading for the life of 62-year-old Mr Bigley, and then his clearly fragile mother made her first television broadcast. With tear-filled eyes and a quiet, faltering voice, she said: "Would you please help my son? He is only a working man who wants to support his family. Please show mercy to Ken and send him home to me alive. His family need him. I need him."

Mrs Bigley, known as Lil, had jokingly referred to the vast quantities of tea she has been drinking in an attempt to cope with the continuing trauma. "The hours between 6 and 9 o'clock are the worst," she said. Messages of the execution of both American hostages were posted on the internet at around 7pm on two consecutive nights. Her condition in hospital was described last night as stable.

The struggle for Kenneth Bigley's life was being fought out in the most public way possible ­ across the airwaves, newspapers and websites of the global media.

For Abu Musab al-Zarqawi, the twin tools of the internet and video camera have become weapons just as potent as the dull blade he and his henchmen used to behead two Americans held with Mr Bigley.

Leaders on both sides of the Atlantic have been quick to condemn the Jordanian extremist and his terror group, Tawhid and Jihad (Unification and Holy War) as barbarians.

But yesterday, there was increasing recognition that they are also sophisticated tacticians with an ability to generate a repulsed but rapt global audience for their cause.

While politicians continue behind-the-scenes efforts, Mr Bigley's fate now seems to lie in the effectiveness of two media campaigns, one waged by his captors to maximise their influence, the other by his family ­ advised by Foreign Office officials ­ to persuade them to "show a gram of human decency". Among a string of appeals from the family was the first from Mr Bigley's 42-year-old Thai wife Sombat Bigley, who read a statement written with the assistance of the Foreign Office.

Speaking from the garden of a Bangkok hours, she clutched photographs from their wedding seven years earlier as, between sobs, she asked the hostage takers from the Tawhid and Jihad group in Iraq for mercy. "My husband Ken is an ordinary, hard-working, family man who wanted to help the people of Iraq," she said. "As a loving wife, I beg you once more for mercy."

Paul Bigley, the brother of the captive British engineer, who on Thursday night credited the Arabic television station al-Jazeera with helping to win a "stay of execution" following the broadcast of Mr Bigley's 11-minute plea for mercy on Thursday, made clear the importance of publicity in the efforts to save his life. He said: "We would ask that our message is played over and over and over on the media so the kidnappers will see it." The result has been the evolution of a dark and very modern drama spawned from messages and scratchy videos placed anonymously on Islamist websites, played out before a global audience almost immediately on 24-hour television news channels.

It is a drama staged not in the corridors of Whitehall or Washington but in the living room of the Bigley family home in Liverpool and an anonymous white room, somewhere in Iraq, where the Briton's pleas and the beheadings of his two American colleagues have been filmed.

Experts said the video released late on Thursday night of Mr Bigley delivering a direct appeal to Tony Blair represented a new level of sophistication in the tactics of Tawhid and Jihad. With frequent references to his captors' demands for the release of female prisoners, the injustice of the occupation and references to Mr Blair, Whitehall sources said it was likely that Mr Bigley was at least following a loose script laid down by al-Zarqawi in response to events in Britain. Dr Toby Dodge, a Iraq expert at Queen Mary University of London, said: "What we are seeing is a deliberate campaign and use of spectacle, through video and websites, to bring a huge amount of pressure to bear on the British and US governments.

"There is no doubt this group has seen the huge amount of concern in the UK and they have interjected in the process.

"Mr Bigley's plea is about highlighting the impotence of the British government in general, and Mr Blair in particular. There is an increasing awareness that they can begin to influence a domestic audience."

The use of the internet and video has been picked up from al-Qa'ida, with which al-Zarqawi is allegedly linked. While al-Qa'ida pioneered the use of websites and encouraged the recording of "living wills" by suicide bombers, Tawhid and Jihad has taken the tactic to new levels.

Their videos of the beheadings of other hostages, are freely available on DVDs sold in Baghdad's markets for as little as 75p.

But while observers have been taken aback by Tawhid and Jihad's media campaign, the response of Mr Bigley's family has been no less impassioned or inspired.

On Monday, his brother Philip and son Craig appeared to break ranks with the Foreign Office's advice by issuing an angry appeal for a "blinkered" prime minister to do more to secure his release. Early on Tuesday, Paul Bigley, who has remained in his home near Amsterdam, made a vehement attack on Mr Blair, vowing to hound him from office if his brother is killed.

Both statements were played on Arabic television stations, including al-Jazeera and al-Arabiya. But it would be wrong to consider the cold demands of the kidnappers and the desperate pleas of relatives as random events.

As each day has passed, a grim pattern has emerged.

A message has been placed on a Arabic website, often signed Abu Maysarah al-Iraqi, a pseudonym for a contributor who posts messages for Tawhid and Jihad, between 7pm and 8pm. Whether deliberate or not, experts point out they coincide with lunchtime American news broadcasts and late evening news in Britain to maximise the impact of the statements and subsequent video footage.

In a similar vein, the televised statements of the Bigley family have appeared carefully tailored for an Arabic audience. A plea to the kidnappers made late on Thursday by Craig, 33, called on the hostage takers to be "all-merciful", a phrase frequently used in Arabic.

Amid growing signs that British and American officials' attempts to hold talks with Sunni clerics linked to militant groups were unlikely to yield concessions, it seemed that the only channel of communication in this grim game of emotional tit-for-tat, a macabre bargaining for human life, was over the airwaves.

HOW THE DAY UNFOLDED

Wednesday 8pm Video of Ken Bigley pleading to Tony Blair for his freedom released on the internet

11pm A militant group claims to have beheaded two Italian aid workers who were kidnapped on 7 September

Thursday 9am The Iraqi authorities confirm that no female prisoners are to be released, but deny bowing to pressure from the US

10am A second Islamist militant group claims to have beheaded the same two missing Italian aid workers

10.30am Paul Bigley, Ken's brother, accuses the US of sabotaging efforts to free him by refusing to release the female Iraqi prisoners

11am Sombat Bigley, the wife of Ken, makes an emotional appeal for the release of her husband

4pm Paul Bigley urges the Irish Prime Minister, Bertie Ahern, to intervene, making reference to the family's Irish roots

5pm Tony Blair speaks to the Bigley family for a second time as their agonising wait continues

6pm Elizabeth Bigley, the elderly mother of Ken, urges his kidnappers to "show mercy" to her son in an emotional appeal from the family's home city of Liverpool