Labour MP Jo Cox has died after being shot and stabbed in the street outside her constituency advice surgery.
The mother of two was attacked by a man reportedly shouting “Britain first” at lunchtime in Birstall, West Yorkshire.
Temporary chief constable for West Yorkshire Dee Collins told a news conference: “I am now very sad to have to report that she has died as a result of her injuries.”
Ms Collins expressed her deepest condolences to the family and friends of Ms Cox, who had two children aged three and five.
She said: “Jo was attacked by a man who inflicted serious and sadly, ultimately fatal injuries. Subsequently there was a further attack on a 77-year-old man nearby who has sustained injuries that are non-life threatening.”
She added: “This is a very significant investigation with a large number of witnesses being spoken to at this time.
“It’s a large and significant crime scene and a large police presence with a full investigation is under way to establish the motive for this attack.”
Ms Collins continued: “Shortly afterwards a man was arrested nearby by local uniformed police officers. Weapons, including a firearm, have also been recovered.
“At 1.48pm Jo Cox was pronounced deceased by a doctor who was working with a paramedic crew that were attending to her serious injuries.
“This is a very significant investigation with large numbers of witnesses that have been spoken to by police at this time. There is a large and significant crime scene and there is a large police presence in the area.
“A full investigation is under way to establish the motive for this attack.”
Labour leader Jeremy Corbyn said the country would be “in shock at the horrific murder” of the MP, who was a “much loved colleague”.
The alleged gunman has been named locally as Tommy Mair, 52, who neighbours in Birstall have described as “a loner”.
The whole of the Labour family, and indeed the whole country, is in shock and grief at the horrific murder of Jo Cox pic.twitter.com/obic5pOCS3
— Jeremy Corbyn (@jeremycorbyn) June 16, 2016
Labour leader Jeremy Corbyn released a statement saying: “The whole of the Labour Party and Labour family – and indeed the whole country – will be in shock at the horrific murder of Jo Cox today.
“Jo had a lifelong record of public service and a deep commitment to humanity. She worked both for Oxfam and the anti-slavery charity, the Freedom Fund, before she was elected last year as MP for Batley and Spen – where she was born and grew up.
“Jo was dedicated to getting us to live up to our promises to support the developing world and strengthen human rights – and she brought those values and principles with her when she became an MP.
“Jo died doing her public duty at the heart of our democracy, listening to and representing the people she was elected to serve. It is a profoundly important cause for us all.
“Jo was universally liked at Westminster, not just by her Labour colleagues, but across Parliament.
“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.
“We send them our deepest condolences. We have lost a much-loved colleague, a real talent and a dedicated campaigner for social justice and peace. But they have lost a wife and a mother, and our hearts go out to them.”
Labour’s deputy leader Tom Watson said: “The whole of the Labour movement is devastated at Jo’s death. We have lost a colleague so young who had much more to contribute to public life. She was our future.
“It is hard to comprehend how a compassionate, principled and beautiful person can be taken away from us so cruelly. It’s even more devastating because she was doing what she did best – serving her constituents.
“We grieve her loss. Our love and prayers are with Brendan and Jo’s family.”
The murder shocked Westminster and led to the suspension of campaigning in the EU referendum.
Prime Minister David Cameron said: “The death of Jo Cox is a tragedy. She was a committed and caring MP. My thoughts are with her husband Brendan and her two young children.”
Home Secretary Theresa May said it was a “dreadful event” adding that Westminster had lost one of its “brightest and most popular” MPs.
Eyewitness Clarke Rothwell, who runs a cafe near the murder scene, described the attack, telling the Press Association: “He was shouting ‘put Britain first’. He shouted it about two or three times. He said it before he shot her and after he shot her.”
He said the gunman fired three shots, the final one at her head.
Britain First is the name of a far-Right group which said it was “not involved and would never encourage behaviour of this sort”.
Another witness, Hichem Ben Abdallah said the alleged attacker was “kicking her as she was lying on the floor”.
He said that after a bystander intervened, the man produced a gun, stepped back and shot Ms Cox.
“He was fighting with her and wrestling with her and then the gun went off twice.”
He added: “I came and saw her bleeding on the floor.”
Mr Abdallah said the weapon looked handmade and that the man who had been wrestling with the assailant continued to do so even after he saw the gun.
He said: “The man stepped back with the gun and fired it and then he fired a second shot. As he was firing he was looking down at the ground.
“He was kicking her and he was pulling her by her hair.”
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.
They did not think he had a job or drove a car and described how he would do gardening chores for local people.
One neighbour, David Pickles, said: “He’s lived there longer than me and I’ve lived here since 1975.
“I still can’t believe it. He’s the last guy I would have thought of.
“He’s just quiet. He kept himself to himself.
“He lived by himself. He’s been on his own for about 20 years.
“I’ve never seen a lot of people visiting or anything like that, but he likes gardening.
“He did a lot of people’s gardens round here. But he did it quietly.”
Another neighbour, who did not want to be named, said: “We’ve known him quite a lot of years.
“I’ve known him since I was young. He lived with his grandmother in that house, she died a few years ago.
“He was a bit of a loner. It’s a bit of a shock – he did everyone’s gardens.
“I can’t say a wrong word about him, he was so quiet.
“It’s come as a shock to everybody.”
Leah Ainley, who lives in Risedale Avenue where Mair was arrested, said armed police surrounded him and pinned him to the ground.
“I just saw them take him down and catch him,” she added.
“The police were armed. There were more than 10 of them at the end.
“I just looked out the window and saw them. The man was white and bald. He
banged his head on the floor.
“He just lay on the floor while they were holding him down.
“He had a bag with him but that’s all I saw, I didn’t see if he was armed.”
Ms Cox was elected to the seat of Batley and Spen at the last general election in 2015.
She was a Remain supporter in the referendum and both official campaigns have suspended their operations as a mark of respect following the attack on her.
She has two children with husband Brendan who shortly after the attack Tweeted a picture of her next to the River Thames, where they lived in a houseboat.
Hoping, praying and thinking of Jo, Brendan and the children. GB
— Gordon & Sarah Brown (@OfficeGSBrown) June 16, 2016
She graduated from Cambridge University in 1995 and worked as an adviser for former Labour prime minister Gordon Brown’s wife, Sarah, and Baroness Kinnock.
Ms Cox was a vocal advocate for the victims of the Syrian civil war and abstained in last autumn’s contentious vote on allowing British military action in Syria.
Mr Cox, a former advisor to ex-Prime Minister Gordon Brown, spent Wednesday campaigning for the UK to remain in the EU.
— Brendan Cox (@MrBrendanCox) June 15, 2016
He posted photographs of himself and the couple’s two young children travelling along the Thames in a dinghy during a counter-protest against a pro-Brexit flotilla of vessels.