Thomas Mair showed no emotion as he was found guilty of the murder of Batley and Spen MP Jo Cox and jailed for life.
Jurors at the Old Bailey had also found the 53-year-old guilty of possession of a firearm with intent to commit murder, possession of an offensive weapon – a dagger – and causing grievous bodily harm with intent to Bernard Carter Kenny.
Mr Kenny, 77, had tried to intervene when he saw Mair attacking 41-year-old Mrs Cox outside Birstall Library on June 16.
Sentencing Mair to a whole life term, Justice Mr Wilkie said: “Because she was a member of parliament your crime has an additional dimension that calls for particular punishment.”
“In the true meaning of the word she was a patriot. You affect to be a patriot.
“You are no patriot. By your actions you have betrays the quintessence of our country - parliamentary democracy.”
He added that Mair had not had the courage to admit what he had done.
Prosecutor Richard Whittam, QC, said it has always been the Crown’s case that Mrs Cox’s murder was a “politically motivated killing”.
The court heard judge Mr Justice Wilkie can impose a life sentence, but would have to impose a minimum term.
Mr Whittam read a victim impact statement on behalf of Bernard Kenny.
It stated: “What you did to me that Thursday afternoon not only threatened my life but changed me as a person and all those around me.”
Mrs Cox’s widower, Brendan Cox, took to the stand to deliver a statement.
He had been in court with Mrs Cox’s parents, Gordon and Jean Leadbeater, and sister, Kim Leadbeater, this morning.
Mr Cox said: “We have no interest in the perpetrator. We only feel pity for him... we are here because we want to tell you about Jo. What she was and what she meant to us.
“Jo was interested in everybody, driven not by her ego but her desire to help. She was connected to her community and proud of the world.”
He told the court that he believed her killing was an act of terrorism.
Mair, of Lowood Lane, Birstall, shot and stabbed mother-of-two Mrs Cox as she arrived at the library in West Yorkshire for a surgery on June 16, a week before the EU referendum.
The court heard he shouted “Britain first”, had a stash of neo-Nazi material at his home and had collected a dossier on Mrs Cox, who was supporting the Remain campaign.
At the conclusion of the prosecution case, Mair’s barrister Simon Russell Flint, QC, called no evidence on behalf of Mair.
Bringing the prosecution case to a close yesterday, Richard Whittam, QC, said: “The sheer brutality of her murder and the utter cowardice of her murderer bring the two extremities of humanity face to face.”
He went on to detail the initial attack on the Batley and Spen MP by defendant Thomas Mair.
He said: “Most likely Jo Cox was shot once in the head followed by a brutal attack with a dagger.
“Despite the element of surprise and the inequality of arms he failed. Perhaps he underestimated the courage and tenacity of Jo Cox.”