“PERHAPS we could snatch him off the street, kidnap him, take him to Paris and deal with him properly there.”

The remark stopped the conversation across the lunch table just as if a waiter had dropped a glass, smashed a plate or thrown water in a customer’s face. Reda Hassaine peered through the fug of his own cigarette smoke at his French paymaster, trying to gauge how serious the suggestion had been. The silence remained unbroken, the word “kidnap” hanging in the air between them.

Hassaine did not know what to say. His job was to move quietly, unobtrusively inside the mosque, to write reports, to feed information back to Jérôme, the man with whom he was now lunching. No one had said anything about snatching Abu Hamza off the streets of London.

Jérôme, the immaculate “diplomat” from the French embassy, smiled at his companion’s discomfort. “Something has to be done. Chevènement says he cannot sleep on Thursday nights wondering what threat is going to emerge from the London Algerians the next morning or what Abu Hamza is going to say in his Friday sermon. Paris is very anxious that they will threaten France again.”

Jean Pierre Chevènement, France’s Minister of the Interior, had one worry in particular. It was March 1998. In a few months the football World Cup was to be held in France, and it was a huge security headache. Algerian terrorists of the Armed Islamic Group (GIA) had bombed the Paris Métro in 1995, and the architects of that atrocity — regarded in France as a deadly enemy — were still on the loose, living untroubled lives in London. The World Cup offered them an opportunity, and there were whispers in the intelligence world that something was being planned. It might take only a word from their spiritual guide Abu Hamza, an article in his newsletter, or a line in a communiqué pinned to the Finsbury Park mosque noticeboard to set the wheels in motion.

Friday was consequently the busiest day of the week for Hassaine, a former journalist and fledgling spy. On Fridays it was imperative that he heard Abu Hamza preach, made a mental note of any proclamations on the board and picked up a copy of the newsletter.

There had been panic in 1997 when a newsletter carried a GIA logo in which the letters were arranged in the shape of a triangle.

Was it a signal that terrorists were going to target the Eiffel Tower? In 1994 four GIA men had hijacked an Air France jet in Algiers and threatened to fly it to Paris and smash into the tower. The plane was stormed by French commandos at Marseilles and the terrorists killed.

France was on edge. Such was her anxiety about the World Cup that she demanded co-operation from her European neighbours. Where she deemed that collaboration was lacking, or less than enthusiastic, she was sending teams of agents abroad to gather intelligence on Islamist militants. Hassaine was part of the team in London, recruited by France’s DGSE intelligence service, to be a spy inside Finsbury Park’s Algerian community and its mosque.

Hassaine had fled Algeria after the GIA killed some of his closest friends and threatened his life. He was motivated by anger and a burning need to see justice done. Although he was married with a young son, and the entire enterprise made him feel nervous and unsafe, some sense of righteous purpose carried him on, recklessly risking his safety.

He had been working for the man he knew as Jérôme for several months when the idea of kidnapping Abu Hamza was lobbed like a grenade into a long lunch at the Bangkok Brasserie, a basement Thai restaurant that was one of their regular haunts.

This was, the Frenchman said, “the ideal place” for their meetings. Located in London’s clubland, the traditional haunt of spies, it was below street level, hidden from view on the corner of St James’s Street and Piccadilly. No one could see in from the street. Jérôme insisted that he and Hassaine always arrived for lunch at 12.30 pm to ensure that they got the table in the far corner, from where he could see everyone who came and left.

Hassaine finally ended the silence. He leaned across the table, and spoke nervously. “How would we do it?” he asked, fervently hoping that there would be no “we”, that this was something he would not have to be involved in.

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