London: A man obsessed with Nazis and white supremacism was sentenced to life in jail on Wednesday for the murder of British lawmaker Jo Cox in a frenzied street attack which stunned Britain a week before the European Union referendum.

Thomas Mair, 53, shot Cox three times and repeatedly stabbed the 41-year-old mother of two young children in her northern English electoral district.

During the attack on June 16, he shouted "Britain first" and "Keep Britain independent" his trial heard, and when arrested he told officers he was a political activist.

Mair, slight of build and balding with a grey goatee beard, had refused to enter a plea or speak in his defence at the Old Bailey trial.

He asked to make a statement only after the jury unanimously returned a guilty verdict but judge Alan Wilkie turned down his request.

"You are no patriot," Wilkie told him. "By your actions you have betrayed the quintessence of our country: its adherence to parliamentary democracy."

He added: "It is clear ... that your inspiration is not love of country or your fellow citizens, it is an admiration for Nazism and similar anti-democratic white supremacist creeds."

Mair, who was charged under anti-terrorism legislation, was also convicted of grievous bodily harm after he stabbed a 77-year-old man who had gone to Cox`s aid during the attack.

"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 Crown Prosecution Service (CPS) said in a statement.

Cox had only been in parliament for little more than a year, winning the seat for the opposition Labour party in the area where she grew up by a large majority.

Her murder a week before the referendum led to the suspension for several days of campaigning ahead of the EU vote which had become increasingly ugly and included bitter personal recriminations, with the issue of immigration key.