Mohiussunnath Chowdhury said he had crisis of conscience over UK arms sales to Saudi Arabia

A cab driver has been found not guilty of a terror charge after police caught him with a 42-inch sword outside Buckingham Palace.

Jurors were unanimous in acquitting Mohiussunnath Chowdhury, 27, of one allegation of preparing acts of terrorism after a retrial at the Old Bailey.

Two unarmed officers suffered cuts to their hands when they disarmed Chowdhury with CS spray on Constitution Hill, outside the palace, on 25 August last year. The prosecutor, Timothy Cray, said Chowdhury had planned to die as a martyr, fighting in the name of Allah, after the terror attacks at Westminster and London Bridge last year.

But he denied the charge, claiming that he had wanted to get himself killed after suffering a crisis of conscience prompted by UK arms sales to Saudi Arabia for its bombardment of Yemen.

Chowdhury bit his lip, raised his eyebrows and saluted jurors who spent 11 hours and 36 minutes considering their verdict. “It should never have happened,” a woman in the public gallery cried in the moments after it was given.

Chowdhury’s acquittal came despite jurors in the latest trial seeing a number of drawings of violent scenes found in his cell while he was on remand in Belmarsh. One showed a man with an AK-47-style gun shooting a police officer outside Downing Street; another showed a plane flying into one of the Twin Towers.

On 25 August last year, Chowdhury had set off from his home in Kirkwood Road, Luton, arriving at Buckingham Palace after his satnav initially sent him to a pub called the Windsor Castle.

He swerved in front of a marked police van and crashed into a set of bollards, before waiting in the vehicle for police to approach. One told the court that Chowdhury had screamed “Allahu Akbar” while wielding a sword.

In his defence, Chowdhury said he had been lonely and depressed, and that he had told his sister he wanted to die. He said he felt guilty being a UK citizen while Muslims in Yemen were being killed by British weapons that were sold to Saudi Arabia.

“I felt depressed and guilty,” he said. “I felt I was also responsible for the decisions taken by my government while my family were dying.

“I had to shun these people, and show my disapproval. At the time I did not know not to do it. There was nothing I could do. I just wanted to disassociate myself from my government’s decision.”