Two men have been cleared of planning to behead a poppy seller, soldier or a police community support officer (PCSO) during Remembrance Day commemorations.
An Old Bailey jury heard they had been accused of plotting an attack inspired by so-called Islamic State (IS).
Yousaf Syed, 20, of High Wycombe, was found not guilty of preparing a terrorist act in 2014, after a retrial.
Co-accused Haseeb Hamayoon, 29, of west London, was cleared by the judge after the jury failed to reach a verdict.
Prosecutors confirmed they would not seek a highly unusual third trial for Mr Hamayoon.
Mr Syed’s cousin, Nadir Syed, 23, of Hounslow, west London, was convicted of preparing for the attack at the end of the first trial last year.
The prosecution of the three men was the first case to come before the courts of an alleged attack plan in the UK linked to Syria in which none of the defendants had actually travelled there.
The case was one of seven referred to in Parliament by Prime Minister David Cameron as part of evidence of the threat posed by IS, or its alleged supporters.
But throughout both trials Yousaf Syed and Mr Hamayoon denied playing any part in planning an attack, saying that while they had shared gory IS-related material among friends online, there was no evidence of a plot in Britain.
Mr Syed was acquitted on Wednesday but the outcome could not be reported while the jury continued to deliberate over Mr Hamayoon.
When he was acquitted, Mr Syed was overcome with emotion and held his head in his hands.
For his part, Mr Hamayoon stood up in the dock, smiled, and thanked both the prosecution and his defence team.
Nadir Syed will be sentenced on 23 June and faces a potential life sentence.
During the two trials, prosecutors said the three men shared an extremist mindset and an obsession with the killing of Fusilier Lee Rigby, in Woolwich.
In the weeks leading up to Remembrance Sunday in 2014, the Syed cousins had recorded a video in which they stamped on a poppy and said it should go to hell.
During his defence Yousaf Syed said he bore no ill will to British soldiers, but he had been angry about British foreign policy and the plight of Muslims around the world.
The pair were also accused of trying to reach Syria in early 2014.
At his first trial Yousaf Syed said that he had simply gone on a cultural holiday to Turkey – but admitted at the second he had wanted to fight against the Syrian government of President Bashar al-Assad.
All three were arrested hours after Mr Hamayoon and Nadir Syed bought a large chef’s knife, days before the annual commemorations.
Yousaf Syed was not present when the knife was bought but prosecutors alleged that he had intimate knowledge of a developing plan.
Mr Hamayoon said that as a trained cook he was buying professional kitchen equipment for his new family home and had been advising his friends to do the same.
The Pakistani national, who had moved from Australia to the UK through marriage, said he regretted sharing extremist material with his new friends in London, saying that he had only taken part in chats about the conflict in Syria in the hope of fitting in.
Read more: http://www.bbc.co.uk/news/uk-36550155