Labour MP Jo Cox has been shot and killed in an attack in her constituency outside Birstall Library today.
According to eyewitnesses the Batley and Spen MP was shot three times and attacked with a knife during the incident in Birstall, West Yorkshire.
Police have confirmed 41-year-old mother of two has now died.
Acting Chief Constable Dee Collins told journalists at a press conference that the police believe it was a “lone gunman” acting on his own.
“The most important fact here at the moment is that we have one male under arrest.”
A 77-year-old man was also injured in the attack but his wounds are not said to be life threatening.
Ms Collins said they were appealing for witnesses to try and understand exactly what happened in this “terrible” case.
“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.”
Jo Cox died within an hour of the attack as doctors fought to save her life. Since the news of her death was announced tributes have been pouring in from MPs from all Parties.
Labour Party leader Jeremy Corbyn said:
“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 Cox 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 Cox died doing her public duty at the heart of 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”
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.”
Paddy Ashdown and many others took to Twitter to share their grief and tribute
“Jo Cox: indomitable fighter for the rights of refugee and immigrants. She represented the best of our politics. There are too few like her.” Paddy Ashdown
“Lost a good MP & loving mum. Recently Jo Cox told some of us about applying calamine lotion to her child’s chicken pox spots. Mums get that.” Caroline Flint MP
“I didn’t know Jo Cox but by all accounts she was a brilliant young MP. And today she was just doing her job. My heart breaks for her family” Nicola Sturgeon
“Devastated that Jo Cox has passed away. She was a great MP & great person, & I can’t begin to imagine the heartbreak of her loved ones. RIP” Imran Hussain MP
“All my love, thoughts and deepest sympathies to friends & family of @Jo_Cox1. Such a horrific crime and a massive loss. There are no words..” Paula Sherriff MP
All EU campaigning has been stopped as a mark for respect for the much respected MP.