British police have charged Thomas Mair with killing Labour MP Jo Cox on a street in northern England. He will appear in court in London as part of formal proceedings.

"We have now charged a man with murder," West Yorkshire Police's Detective Superintendent Nick Wallen said in a statement early Saturday.

Thomas Mair, from Birstall - the northern English town where the 41-year-old mother of two was shot and stabbed to death - was arrested shortly after the attack on Thursday.

He will appear at Westminster Magistrates Court later on Saturday where he is expected to be remanded in custody.

As well as murder, Mair has been charged with grievous bodily harm, possession of a firearm with intent to commit an indictable offense and possession of an offensive weapon.

Cox, who had been an MP for Britain's Labour party for just a year, was attacked as she got out of her car along with two aides. The attacker stabbed her with a hunting knife and shot her as she lay on the ground.

Earlier, police said they were investigating Mair's alleged links to a neo-Nazi movement and an interest in anarchist weapons literature. At least three eyewitnesses described how the 52-year-old, who has a history of mental illness, shouted the term "Britain First" during the attack, a reference to a far-right political party and movement.

A regional counterterrorism unit is aiding in the investigation, in part to determine any links with other extremists, but Mair is believed to have acted alone.

Cox's murder has left many Britons stunned, coming a week before the country was due to vote in a referendum on Britain's EU membership. Campaigning has been temporarily suspended, amid concerns that the often-times heated tone of the debate contributed to her death.

German Chancellor Angela Merkel has called for political rhetoric to be toned down following the killing.

Questions are also being asked about how Mair was able to acquire a gun in a country with tough firearms controls.

US President Barack Obama spoke to Cox's husband Brendan by phone from Air Force One on Friday and offered his condolences on behalf of the American people, the White House said in a statement.

"The president noted that the world is a better place because of her selfless service to others, and that there can be no justification for this heinous crime, which robbed a family, a community, and a nation of a dedicated wife, mother, and public servant," the statement said.

An online fund to raise money for Cox's favorite charities had amassed more than £200,000 (254,000 euros) in just five hours.

(DW)