Jo Cox dead: Labour MP fatally shot and stabbed outside constituency surgery in Birstall, West Yorkshire

Husband leads tributes to rising star of Westminster and urges people to ‘fight against the hate that killed her’

Jo Cox was elected at the 2015 general election (PA)

MPs from across the political spectrum have set aside their differences to pay tribute to one Parliament’s most promising young MPs who was killed in the street in her constituency. Her suspected killer is a man police are investigating for possible far-right links.

Jo Cox, who helped spearhead the campaign to help Syrian refugees, was shot three times outside her constituency advice surgery in Birstall, West Yorkshire.

The suspect, who was arrested at the scene, was named locally as Thomas Mair, aged 52. He was reported to have shouted “Britain First” during an attack in which he fired three shots from close range while at the same time stabbing the MP with a knife.

Security sources told The Independent that police were investigating Mair’s possible interest in far-right politics and pro-apartheid South Africa.

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

David Cameron and Jeremy Corbyn led the tributes to Ms Cox, a mother of two young children, who had only been elected as an MP in 2015.

Ms Cox is the first MP to have been fatally attacked while in office in more than quarter of a century.

Both sides in the European Referendum campaign cancelled events due to be held on Friday as a mark of respect. Flags across Whitehall were lowered to half mast.

Her husband Brendan said the family was going to work “every moment of our lives” to “fight against the hate that killed Jo”.

"Jo believed in a better world and she fought for it everyday of her life with an energy, and a zest for life that would exhaust most people,” he said.

"She would have wanted two things above all else to happen now, one that our precious children are bathed in love and two, that we all unite to fight against the hatred that killed her.

"Hate doesn't have a creed, race or religion, it is poisonous.”

Labour leader Jeremy Corbyn was among colleagues from all parties at a vigil for Jo Cox in Parliament Square (AFP)

Mr Corbyn said Ms Cox died “doing her public duty at the heart of our democracy”.

“In the coming days, there will be questions to answer about how and why she died. But for now all our thoughts are with Jo’s husband Brendan and their two young children. They will grow up without their mum, but can be immensely proud of what she did, what she achieved and what she stood for.”

Mr Cameron added: “She had a great track record of caring about refugees and had taken a big interest in how we can look after Syrian refugees and do the right thing in our world. She was a star for her constituents, a star in Parliament and a star right across the House.”

Police refused to speculate on what motivation lay behind the attack, but witnesses reported hearing her attacker shouting “Britain First”, which may be a reference to the far right BNP splinter group.

Ms Cox had been a high profile campaigner for the rights of Syrian refugees and was fighting to force the Government to take in more asylum seekers.

“He was shouting Britain First when he was doing it,” said 38-year-old Graeme Howard.

“He was pinned down by two police officers and she was taken away in an ambulance.”

(PA (PA)

Clarke Rothwell, who runs a cafe near the murder scene, added: "He was shouting 'put Britain first'. He shouted it about two or three times."

Britain First is the name of a far-right BNP splinter group. It issued a statement saying it was "not involved and would never encourage behaviour of this sort".

Mair's house was sealed off by police who were guarding the property as forensic officers worked in the garden.

Neighbours said he had lived there for more than 30 years - on his own for the last two decades since the deaths of his mother and grandmother. "He's lived there longer than me and I've lived here since 1975,” said one.

"I still can't believe it. He's the last guy I would have thought of. He likes gardening.

"He did a lot of people's gardens round here.”

Politicians from across all major parties expressed their shock at Ms Cox’s untimely death.

Theresa May said Ms Cox was one of the "brightest and most popular" MPs and the pain her family and friends are suffering is "unimaginable".

"It is entirely appropriate that all campaigning for the referendum has been suspended,”

"All of us are united in our deep sadness at the loss of one of our brightest and most popular Westminster colleagues."

The former Prime Minister Gordon Brown, who knows Ms Cox well from when she worked with his wife Sarah, said: "Jo Cox was the most vivacious, personable, dynamic and committed friend you could ever have. Whenever you talked to her, the compassion in her eyes and the commitment in her soul shone through.

"Sarah and I were privileged to work with Jo and her husband Brendan over many years and in her tireless efforts on behalf of poor and desolate children and mothers. She she went to some of the most dangerous places in the world. The last place she should have been in danger was in her home town.”

Ukip leader Nigel Farage said: "Deeply saddened to hear that Jo Cox has died. Sincerest condolences to her family."