Three British men were convicted of plotting terrorist bombings that prosecutors said were intended to be bigger than the 2005 London transit attacks.

A London jury found Irfan Naseer, 31, and Irfan Khalid and Ashik Ali, both 27, guilty of being central figures in the foiled plot to explode knapsack bombs in crowded areas — attacks potentially deadlier than the July 7, 2005 explosions on subway trains and a bus which killed 52 commuters.

Judge Richard Henriques told the men — who had been arrested in September 2011 — they will all face life in prison when sentences are imposed in April or May for plotting a major terrorist attack in Birmingham, a city of roughly 1 million people located about 200 kilometres northwest of London.

“You were seeking to recruit a team of somewhere between six and eight suicide bombers to carry out a spectacular bombing campaign, one which would create an anniversary along the lines of 7/7 or 9/11,” he told them after the jury reached its verdict.

“It’s clear that you were planning a terrorist outrage in Birmingham.”

He addressed Naseer directly, calling him a “highly skilled bomb maker and explosives expert” who had tried to persuade his colleagues that it was “far preferable” to launch a terror attack inside Britain rather than fighting jihad abroad.

Prosecutors said the Muslim men, fired up by the sermons of a U.S.-born al-Qaeda preacher, hoped to cause carnage on a mass scale. Their plot was undone by mishaps with money and logistics, and ended in a police counterterrorism swoop in 2011.

By then, the plotters were still experimenting with chemicals and had not assembled any bombs.

'Catastrophic' consequences

Special prosecutor Karen Jones said the men’s final targets had not been set, but that their potential for killing people and destroying property should not be underestimated. She said two of the men had received training in Pakistan before returning to Britain to plan attacks.

“Had they not been stopped, the consequences would have been catastrophic,” she said.

She said the conviction showed that even when preparations for acts of terrorism take place abroad, perpetrators will face justice in British courts.

The three had pleaded not guilty to charges of preparing for terrorism.

But the jury at Woolwich Crown court agreed with prosecutors that the trio were the senior members of a homegrown terror cell inspired by the anti-Western sermons of U.S.-born Muslim cleric Anwar al-Awlaki, who was killed in Yemen in September 2011.

The suspects convicted on Feb. 21 were among 12 people arrested in September 2011 in counterterrorism raids in Birmingham.

Several other suspects have pleaded guilty to offences related to the plot.