When Walid Saadaoui recruited Amar Hussein to join him in a pogrom on the streets of Greater Manchester, Hussein wept with joy.

For years, the two men had been sleeper agents for the Islamic State terrorist group. Each had lived quietly in Britain for years, waiting for the right moment to stage an attack, and for the right person to give them the support to make it happen.

Now, finally, it seemed that “zero hour” – as they called it – had arrived.

They planned to disguise themselves as Jews to infiltrate a march against antisemitism in Manchester city centre, before opening fire on the crowd with assault rifles.

The pair hoped to throw emergency services into chaos by paying people to make 999 calls across Greater Manchester, allowing them to slip away and continue their attack in the suburbs at the centre of the region’s Jewish community.

Saadaoui also planned to attack Christians, saying: “God willing … after we finish with the Jews … we move on to the crusaders.”

It would have been, according to senior detectives, the worst terrorist attack the UK had ever seen.

Both men envisaged being “martyred”, but neither reckoned with the prospect that a man they believed to be a crucial player in their plot could be a counter-terrorism undercover operative (UCO). Because of the courage of the UCO, known as “Farouk”, Saadaoui was captured in the final stages of preparation in a hotel car park, while Hussein was arrested at the shop where he worked.

A prosecution source said of Saadaoui, the prime mover: “This was a man who was quite prepared to go out and kill children and leave his own in the process.” They added: “At one point he says: ‘You know, if we have an AK-47 left over, I will leave it for my son – so he can do what I do when he grows up.’”

The disturbing mindset and tactics of the secret IS network of “lone wolves” and sympathisers were revealed in unprecedented detail in a forensic prosecution case laid out in a three month trial at Preston crown court.

Now that Saadaoui, 38, and Hussein, 52, have been convicted of preparing for acts of terrorism, and Saadaoui’s younger brother Bilel Saadaoui has been convicted of failing to report them, the full story of the plot can be told.

A personable man who doted on his pet birds

On the surface, nothing about Saadaoui, a father of two, suggested he was an extremist who, in his own words, believed Adolf Hitler should be “exulted”. Originally from Tunisia, he was not known to police or security services, had never been referred to the Prevent anti-radicalisation scheme and had no criminal convictions.

He came across as a personable, ambitious individual with little interest in religion, let alone extremism. Acquaintances in the UK knew him as a man who doted on his pet birds, dressed casually in sportswear and said he wasn’t a faithful Muslim. When he met his first wife, a British woman, he was working as an entertainer at a Tunisian resort, amusing tourists by the pool with jokes, fitness sessions and dance shows.

The couple settled in Clacton-on-Sea, Essex. Saadaoui worked at a Haven holiday village, doing overtime in the resort’s shops, bakery and arcade, before training as a chef and buying an Italian restaurant, the Albatross, in Great Yarmouth, Norfolk, in 2018. His marriage ended soon after moving there, and he went on to meet his second wife, with whom he he had two children.

“I wanted to progress in life,” Saadaoui claimed seven years later, standing in the dock at court.

The truth was much darker.

“Walid Saadaoui told Farouk that [he and his brother Bilel] committed to Islamic State when they were young boys in Tunisia,” a prosecutor in the case told the Guardian. “And so that became a driving force for them. And by [the time they were] late teenagers, early 20s, they both got into the tourism industry and befriended English girls and married to come to the UK. They moved into the UK with a very ingrained Isis [IS] creed and conviction.”

“Their partners were, without doubt, without knowledge of what was happening,” the source added. “The [brothers] would go off and speak in Arabic together.”

Saadaoui hated mosques, calling them repugnant. He preferred private prayer groups and online Facebook pages where extremists were drawn together by signifiers, such as Saadaoui’s avatar – a picture of the Paris Bataclan terrorist Abdelhamid Abaaoud, whom he idolised.

Saadaoui used 10 Facebook accounts to revel in attacks on Jewish people, individual terrorist tactics and disseminate IS propaganda, produced by the group’s media agency, al-Furqan. By 2023 he had moved to Wigan, in Greater Manchester, 20 miles west of one of Europe’s largest Jewish communities, ostensibly to be nearer his brother.

To the Saadaoui brothers, even Hamas members were moderate “apostates”. But in 2023, the 7 October attack on Israel became an inspiration. Saadaoui’s antisemitism intensified, along with his desire to stage an attack in the UK.

The undercover operation

Five days after the atrocity in Israel, he bought an airgun to start practising. On 26 October, he posted an image online of a man preparing to go to war and leaving his children behind.

Unknown to him was counter-terrorism police’s immersion in north African jihadist subcultures. This meant Saadaoui, a cautious, secretive individual who had spent years mentally preparing to execute a terror attack, truly believed he had met a fellow IS sympathiser when he began corresponding on Facebook with Farouk in December 2023, the same month he posted on the social media site: “I pray to you Allah not to catch me until I break my thirst with Jewish, Christians and their proxies’ blood.”

Saadaoui believed Farouk could get him semi-automatic weapons, sent by divine intervention. He paid a £2,250 cash deposit at their first meeting. It was vital that Farouk let him think he could arm him, as Saadaoui had tried to source guns through Albanian gangsters and police wanted to stop him from getting guns from elsewhere. Farouk had to persuade him he could get AK-47s from Morocco and maintain that ruse until he could be arrested at a handover.

Police could have arrested Saadaoui earlier on the basis of his Facebook posts. However, prosecution for those offences would lead to him “being released in a year or two – and then becoming more of a threat”, a senior detective in the case said. But while they believed the undercover investigation was containing the threat from Saadaoui so “the public was never at risk”, the detective admitted the tactic gave him sleepless nights. “There was more than one occasion I thought, what on earth was I doing? What if he goes and does something?” he said.

Around the same time he befriended Farouk, Saadaoui recruited Amar Hussein. Describing Hussein’s reaction, Saadaoui said: “I swear to God almighty, this is the first time I saw a man his age crying with tears and hugging me. He said: ‘Bring me a weapon.’”

Frank Ferguson, the head of the Crown Prosecution Service special crime and counter-terrorism division, said: “Amar Hussein had military training and experience – which Walid Saadaoui didn’t.”

Hussein shared Saadaoui’s “jihadist faith”. He lived and worked at Salim Appliances, a white goods repair shop in Bolton. Saadaoui was worried Hussein, an unpredictable, volatile character, would derail their plans by staging a spontaneous attack of his own. He was known for dressing as a follower of IS – including a tool belt that looked like a “suicide belt”. On one occasion, according to Saadaoui, he threatened someone at a restaurant, saying: “I am Daesh [IS] and I came to you with slaughter.”

Describing Hussein’s past to Farouk, Saadaoui said: “He is from a Kurdish background, was brought up in Iraq, trained in Saddam’s army … a devotee of the Islamic State. He doesn’t believe in any heretic civilian institution of all kind.”

After his arrest, Hussein laid the plot’s motivations bare, telling police: “Your prime minister, you know, he is terrorist that kills our children and gives Israel weapon and kill our children. Terrorism is our religion.”

Hussein and Saadaoui travelled repeatedly to Dover in spring 2024 on reconnaissance, observing the port where they believed their weapons – codenamed “goldfinches” by Saadaoui – would be arriving, posing as tourists at the white cliffs.

Hussein and Saadaoui had met through Bilel Saadaoui. Jihadist propaganda found on Bilel Saadaoui’s phone included the statement: “To be in a cold icy night in an army of mujahideen waiting to meet the enemy next morning is more beloved to me than a wedding night with the most beautiful bride who I love, or if I were given the good news of having a newborn son.”

By May 2024, after all their reconnaissance trips, Hussein and Saadaoui believed they were about to receive guns and hundreds of rounds of ammunition from Farouk, after a last trip to Dover. Their preparations were complete. As Saadaoui readied himself to die, he wrote a will and gave it to his brother, having sold the Albatross, placed £74,000 in a safe in his garden and started to teach his wife to drive.

Saadaoui had already joined Jewish Facebook groups looking for marches to attack. He had taken Farouk around neighbourhoods north of Manchester city centre, observing synagogues, shops and schools, looking for targets. As they watched ordinary people, peaceably going about their business, Saadaoui said to Farouk: “My blood is boiling, brother, let’s get out of here.” He told Farouk: “We are going to carry out the operation in August … brothers from inside (Islamic State)… they will help.”

Instead, on 8 May 2024, police executed a sting operation on the car park of the Last Drop Village hotel in Bolton. Saadaoui was caught red-handed. The guns, unbeknown to him, had been deactivated.