British MP murderer a 'dedicated supporter of neo-Nazi group'

Thomas Mair, who made international headlines on Thursday after shooting and stabbing the British lawmaker, had a "long history with white nationalism".

"According to records obtained by the Southern Poverty Law Center Mair was a dedicated supporter of the National Alliance (NA), the once premier neo-Nazi organisation in the United States, for decades," legal advocacy group, the SPLC said on its website.

Receipts published on the advocacy group’s website showed Mair spent more than $620 to purchase reading material from the National Alliance – a group which publically demanded an establishment of an all-white homeland and the eradication of the Jewish people.

Among the publications purchased by the attacker was a manual on building guns from everyday materials – confirming an eyewitness account which suggested Mair held a weapon of “home-made” appearance during the attack.

Other eyewitnesses said he had shouted “put Britain first” repeatedly during the Thursday afternoon attack, referencing a far-right anti-immigration group in Britain which calls for Britons to be prioritised.

Britain First responded with a statement saying it was "obviously not involved" and "would never encourage behaviour of this sort."

Britain’s campaigning for an upcoming EU referendum to debate whether to leave the European Union was halted in response to the attack.

Jo Cox, a 41-year-old member of the opposition Labour Party who was killed in broad daylight, was known for campaigning for refugee rights as well as to ‘remain’ in the EU.

Police confirmed an investigation into the attack was attempting to establish a motive for the murder.