The Southend West MP was stabbed more than 20 times during a constituency surgery in Leigh-on-Sea, Essex on 15 October 2021.

A jury at the Old Bailey took just 18 minutes to convict Ali Harbi Ali of murder and preparing acts of terrorism.

The 26-year-old from Kentish Town, north London, had denied the charges and claimed he targeted the MP over his vote for airstrikes on Syria.

Sir David's family sat in court just a short distance from Ali as the verdicts were delivered.

The judge, Mr Justice Sweeney, said Ali, who refused to stand up in the dock on "religious grounds", will be sentenced on Wednesday.

Before being sent out, the judge told the jury the defendant had no legal defence for killing the Conservative MP.

Following the verdicts, Prime Minister Boris Johnson tweeted that Sir David was "a beloved colleague, public servant and friend", adding that his thoughts were with his family.

Ali stabbed Sir David, 69, after tricking his way into a meeting by pretending to be an NHS employee moving to the area.

During the trial, jurors heard how he had also scoped out and planned attacks on other MPs, including cabinet minister Michael Gove who he believed was "a harm to Muslims".

He drew up plans to get close to the Levelling Up Secretary which he abandoned after he split from his wife and left the family home, the jury heard.

The court heard the defendant was still determined to carry out an attack and scouted the office of Finchley MP Mike Freer and carried out online research on other MPs, including Labour leader Sir Keir Starmer.

He chose Sir David after a search on Twitter showed he was due to hold a constituency surgery.

The trial heard Ali was a "model student" but had become self-radicalised in 2014, dropping out of university and abandoning ambitions of a medical career.

He was referred to the government's Prevent strategy to counter radicalisation, but continued plotting in secret.

In evidence, Ali told the court he wanted to travel to Syria to join the self-styled Islamic State but it was too "difficult" so he decided to "help Muslims here" instead.

He said he had no regrets or shame about killing Sir David, telling the court: "If I thought I did anything wrong, I wouldn't have done it".

Ali said: "I felt like one minute I was sat down at the table talking to him and the next he was, sort of, dead.

"But, yeah, it's probably one of the strangest days... of my life now, you know?"

The court heard the defendant had planned to die as a "martyr", assuming he would be shot by police.

After the stabbing, witnesses described how he waved the knife around and threatened Sir David's staff and members of the public.

He was detained by two plain-clothed officers from Essex Police, the first on the scene, who were armed only with batons and incapacitant spray.

In video shown to the jury, officers were heard shouting "drop the knife" while the defendant was on the phone to his sister.

He told jurors he dropped the weapon when he realised the officers - PC Ryan Curtis and PC Scott James - were unarmed.

Both officers have received Essex Police's highest accolade, the Merit Star, for their bravery.

Recalling when they arrived at the scene, PC James said: "We couldn't stand outside if there was a chance other people were getting attacked, and we also wanted to get paramedics inside the building as soon as possible.

"Our biggest fear that day was that there were other defenceless people inside with Sir David waiting for the police to come through the door - so any fears we had were put to one side."

Det Ch Supt Dominic Murphy, head of operations for the Met Police's Counter Terrorism Command, said: "Sir David's family have been left utterly devastated, but they have shown remarkable courage and dignity throughout the investigation and this trial.

"Following the murder, our officers worked extremely hard and at pace to firstly ensure there was no existing threat linked to the attacker, and then to put together a compelling package of evidence which showed his extremist mind-set, and the lengths he went to in order to plan and commit the attack."

Sir David was killed five years after Batley and Spen MP Jo Cox was murdered in her constituency.

Her widower Brendan Cox said on Twitter: "The terrorist will rot in jail and die in ignominy. David's name will be remembered, especially by the people of Southend who he served."

Jo Cox's sister Kim Leadbeater, the current MP for Batley and Spen, told the BBC there were "two things that really need to be looked at", including ensuring the country had a "free and open society and democracy" and "also how we make sure people elected to public office feel safe to do their jobs".