Judge Michael Astill said the men were intent on causing "indiscriminate death and suffering" as he sentenced them at London's Central Criminal Court to a minimum of between 35 and 40 years behind bars.

"You have betrayed this country that has given you every opportunity," he told them.

The head of the Metropolitan Police's anti-terrorism unit, Peter Clarke, said the five were "trained, dedicated, ruthless terrorists" who had links with al-Qaeda in Pakistan.

The five were among seven men alleged to have conspired to bomb a central London nightclub and shopping centre, bring down a plane as well as hit gas and electricity supplies, killing hundreds in the process.

One of them also discussed trying to buy a radioactive "dirty bomb" from the Russian mafia to be "bigger than 9/11", but nothing appeared to have come from his enquiries, Britain's longest-running terrorism trial was told.

But there were calls for a renewed inquiry after revelations that one of the convicted, Omar Khyam, boasted of working for al-Qaeda's number three, Abdul Hadi, and who also had links to the London suicide bombers in 2005.

This information was kept from jurors during the year-long trial, for fear of prejudicing their deliberations.

US authorities announced last Friday that Hadi, also known as Adbul al-Hadi al-Iraqi, had been captured and taken to the US-run Guantanamo Bay detention camp for security suspects in Cuba.

Khyam, 25, met the presumed ringleader of the London suicide bombings, Mohammed Sidique Khan, in terrorist training camps in Pakistan and at least four times in England, while the former was under surveillance by Britain's domestic intelligence service, MI5, in the final stages of plotting.

He also met another of the bombers, Shehzad Tanweer, but MI5 assessed that Khan and Tanweer were "peripheral" figures.