A white supremacist and "terrorist" has been found guilty of killing Labour MP Jo Cox in a “planned and pre-meditated murder” in the run-up to the EU referendum.

Thomas Mair was convicted by a jury of murdering the 41-year-old mother-of-two outside her West Yorkshire constituency surgery.

The quiet loner was jailed for a whole life sentence for what Ms Cox's widower Brendan branded "a political act and an act of terrorism".

A statement from Jo Cox, found in Thomas Mair's house, talked of her support for the Remain campaign Twitter/ Brendan Cox (Twitter/ Brendan Cox)

Jurors heard how the 53-year-old shouted “Britain first, this is for Britain” over her body after shooting her three times and inflicting 15 stab wounds.

"We are not here to plead for retribution," said Mr Cox, in a statement read out after the verdict.

"We feel nothing but pity for him that his life was so devoid of love and filled with hatred, his only way of finding meaning was to attack a woman who represented all that was good about the country in an act of supreme cowardice.

"It was a political act, an act of terrorism, but in the history of such acts, it was probably the most incompetent and self-defeating."

Husband Brendan Cox paying tribute to the mother-of-two Getty (Getty)

Mr Cox also said the aftermath of the murder had witnessed "Britain at it's best: compassionate, couragious and kind", and that her "energy and her love are hard-wired into our children".

He finished his statement outside the Old Bailey saying he hoped "Jo's death will have meaning" and that "those in politics and the media" will learn from the tragedy.

The court was told how he kept news articles referencing Ms Cox’s support for the Remain campaign, a Third Reich eagle with a swastika, German military history books and news cuttings reporting on Norwegian mass murderer Anders Breivik.

Prosecutor Richard Whittam QC, who is a seasoned terrorism lawyer, branded Mair as a terrorist during the trial, but said it was not necessary to prosecute him as a terrorist.

Mair was prosecuted as a terrorist, hence the trial took place at the Old Bailey in central London and not Leeds, but he was charged with the common-law offence of murder.

Husband Brendan Cox arriving at the Old Bailey Getty (Getty)

The prosecution, as was the case when trying the Lee Rigby murderers, wanted the jurors simply to decide whether he was guilty of carrying out the murder, and not to consider his motives.

Mair attacked Batley and Spen MP Ms Cox at 1.48pm on 16 June as she arrived for a surgery with constituents at a Birstall public library.

As the 5ft-tall MP was being attacked, she told her personal assistant Fazila Aswat and senior caseworker Sandra Major to “Get away you two. Let him hurt me. Don’t let them hurt you”.

On his arrest, he told police officers he was a "political activist" and when he first appeared before magistrates in London, he responded "death to traitors, freedom for Britain" when he was asked his name.

Mair, who has a history of mental illness but did not want this to form his defence, also stabbed 77-year-old pensioner Bernard Kenny in the stomach when he intervened.

In the days leading up to the killing, he searched online for '.22' ammunition and looked at pages containing the question, 'is a.22 round deadly enough to kill with one shot to a human's head?'.

The trial heard there was a billion to one chance that DNA recovered from the murder weapon came from anyone else.

Prosecutor Richard Whittam QC said in his closing speech: "This was a cowardly attack. He shot her in the head, which was followed by a brutal assault with the dagger.

"Despite the element of surprise, he failed in his first attempt. Perhaps he underestimated her tenacity and courage.

Tommy Mair, 52, was detained by police near his home in Birstall, West Yorkshire SWNS (SWNS)

"She pleaded with her two aides to escape, saying, 'let him hurt me, don't let him hurt you'.

"He then attacked her again with the dagger.

"It is our submission that the overall effect of this compellingly establishes the guilt of Thomas Mair as her murderer."

Mr Cox appeared at the trial for the first time on Tuesday, when Mair was scheduled to begin his defence, but no defence case was submitted.

Mair shouted "Britain First, this is for Britain" over Ms Cox's dying body PA (PA)

The court previously heard how Mair had a White Patriot Party Wikipedia printout and a rune stone in a bag with a BBB White Liberation Movement symbol on it.

Jeremy Corbyn, in the aftermath of the verdict, said: "Jo Cox believed passionately that all people can achieve their full potential given the opportunity. Her murder was an attack on democracy, and has robbed the world of an ambassador of kindness and compassion."

Sue Hemming, head of special crime and counter-terrorism at the Crown Prosecution Service, said: ""Mair has offered no explanation for his actions but the prosecution was able to demonstrate that, motivated by hate, his pre-meditated crimes were nothing less than acts of terrorism designed to advance his twisted ideology."

The weapons used by Thomas Mair to murder MP Jo Cox Rex (Rex)

Mair, of Lowood Lane, Field Head Estate, Birstall, who had lived on his own for the past 20 years since his grandmother's death, was also found guilty of inflicting GBH with intent, possession of a firearm and possession of a dagger.

He sat largely emotionless throughout the trial, but rolled his eyes as two black jurors were sworn in, and again when a glowing statement was read out from Ms Cox's long time friend Stephen Kinnock MP.