All four July 21 bombers have been jailed for life for conspiracy to commit murder and have been told they will serve a minimum of 40 years.
Muktar Said Ibrahim, the leader of the group, Yassin Omar, Ramzi Mohammed and Hussain Osman, who attempted to detonate homemade bombs on the London transport network on July 21, 2005, were convicted following a six-month trial at Woolwich Crown Court.
The two other defendants, Adel Yahya and Manfo Asiedu, will face a retrial after the jury failed to reach a verdict in their cases.
The judge said that both the July 7 and the failed July 21 bombers were terror cells operating under the control of al-Qa’eda.
Mr Justice Fulford said: “What happened on July 7 in 2005 is of considerable relevance to this sentencing.
“I have no doubt that they were both part of an al-Qa’eda-inspired and controlled sequence of attacks.”
“This was a viable, indeed a very nearly successful, attempt at mass murder,” he said.
“It was long in the planning and came soon after July 7 – it was designed for maximum impact.”
Sue Hemming, head of counter terrorism at the Crown Prosecution Service, said the men had seen the “devastation” caused on July 7 and “could have been in no doubt about the consequences of their actions”.
The court had heard how it was mere “good fortune” the devices packed with shrapnel did not detonate, potentially killing dozens of commuters and the bombers themselves.
The men all denied the charges, claiming the devices were not intended to go off and were meant as a protest against the Iraq war.
The court had heard how the gang used explosives made of hydrogen peroxide and chapatti flour in an attempt to kill innocent people on three London buses and a Tube train.
Omar’s one-bedroom flat in New Southgate, north London, was used as a bomb factory.
The failed attack came exactly two weeks after the July 7 attacks on London, which left 52 commuters and four bombers dead.
But the prosecution said during the trial that the second attack was a long time in the planning and was not a copy-cat attack.
Ibrahim visited Pakistan at the same time as two of the July 7 bombers, allegedly learning from Mohammed Sidique Khan and Shezhad Tanweer how to make homemade bombs.
The court heard how the British authorities had only ever come across improvised explosive devices made from hydrogen peroxide and organic substances on two occasions: July 7 and July 21.