Claims by three would-be bombers that their convictions over the failed July 21 plot were unfair have been dismissed by the European Court of Human Rights (ECHR).
Judges found there had been no breach of the rights of Somali nationals Muktar Said Ibrahim, Ramzi Mohammed and Yassin Omar.
However they did conclude there was a violation in respect of another applicant, who was convicted of assisting a fourth suspected would-be bomber, and awarded him more than £13,000 in legal fees.
The planned attack came two weeks after 52 people were killed in the 7/7 attacks in central London in 2005.
Ibrahim, Mohammed and Omar were convicted in July 2007 of conspiracy to murder in relation to the July 21 episode and jailed.
They appealed to the ECHR on the basis that they were denied access to lawyers during their initial police questioning, alleging that their subsequent convictions had been unfair because of the admission at trial of the statements they had made during those interviews.
Their claim was thrown out in 2014 but it was later referred to the Strasbourg court's Grand Chamber.
The chamber's judgment, handed down on Tuesday, concluded that at the time of their initial police questioning there had been an urgent need to avert serious adverse consequences for the life and "physical integrity" of the public.
There had therefore been compelling reasons for temporary restrictions on their right to legal advice, it added.
The court did however find there had been a breach in respect of another applicant.
Ismail Abdurahman was convicted in 2008 of assisting a fourth suspected July 21 bomber and failing to disclose information after the attacks.
He was sentenced to 10 years in prison, which was reduced to eight years on appeal.
Abdurahman was not suspected of detonating a bomb and was interviewed as a witness.
He should have been cautioned and offered legal advice when he began to incriminate himself in interview but this was not done.
Police continued to question him as a witness and took a written statement from him before he was arrested.
The ECHR found the government had failed to demonstrate compelling reasons for restricting Abdurahman's access to legal advice and for failing to inform him of his right to remain silent.
It said the consequence of him not being cautioned at the point when he started to incriminate himself was that he was misled as to his procedural rights.
The court found that there had been a violation of Article 6 of the European Convention on Human Rights, which covers the right to a fair trial.
It concluded that it did not follow from the finding that Abdurahman was wrongly convicted, saying "it is impossible to speculate as to what might have occurred had there been no breach of the Convention".
It awarded 16,000 euro (£13,650) for Abdurahman's legal fees.