Labour MP Jo Cox is in a critical condition after she was shot and stabbed in her constituency by a man reportedly shouting "Britain first".

The 41-year-old mother of two was left lying in a pool of blood on the pavement after her assailant shot and stabbed her outside her advice surgery in Birstall, West Yorkshire.

West Yorkshire Police said a 52-year-old man was arrested in connection with the attack, which happened near the town's library.

Clarke Rothwell, who runs a cafe nearby told the Telegraph: "He was stabbing her with a foot-long knife multiple times while shouting 'Britain first, Britain first, Britain first'.

He added: "Three times she was shot, the initial time which then she dropped to the floor, and two more times.

"The third time he got close proximity, he shot her round the head area."

He added: "In the meantime he was stabbing her as well, he was stabbing her with his knife."

Graeme Howard, 38, who lives nearby told the Guardian: "He was shouting 'Britain first' when he was doing it and being arrested. He was pinned down by two police officers and she was taken away in an ambulance."

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 her.

The 56-year-old, who was in the cafe next door to the library, told the Press Association: "There was a guy who was being very brave and another guy with a white baseball cap who he was trying to control and the man in the baseball cap suddenly pulled a gun from his bag.

"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: "He was kicking her and he was pulling her by her hair."

Images circulating on social media apparently showed the gunman being detained, a bag close to where two police officers were holding him.

A police spokesman said officers were called at 12.53 on Thursday to Market Street, Birstall, "where a woman in her 40s had suffered serious injuries and is in a critical condition".

He added: "A man in his late 40s to early 50s nearby also suffered slight injuries. Armed officers attended and a 52-year-old man was arrested in the area."

Ms Cox was elected to the seat of Batley and Spen at the last general election in 2015.

She is 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.

She graduated from Cambridge University in 1995 and has worked as an adviser for former Labour prime minister Gordon Brown's wife, Sarah, and Baroness Kinnock.

Ms Cox has been 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.

Labour leader Jeremy Corbyn said he was "utterly shocked by the news of the attack on Jo Cox. The thoughts of the whole Labour Party are with her and her family at this time."