A Member of Parliament from Boris Johnson's Conservative Party, David Amess, has died after being stabbed.

The lawmaker, who was first elected to Parliament in 1983, was said by witnesses to have been stabbed "multiple times" during his regular 'surgery' session, which MPs traditionally hold to meet and help voters in the area that they represent.

Police and medics rushed to the scene in Leigh-on-Sea, east of London, to treat the 69-year-old.

"He was treated by emergency services but, sadly, died at the scene," Essex Police said.

"A 25-year-old man was quickly arrested after officers arrived at the scene on suspicion of murder and a knife was recovered."

Amess, a father of five, had represented the area since 1997 after previously being MP for Basildon.

Tributes have been pouring in for the MP, whose killing highlights the risk facing lawmakers - in 2016 Labour MP Jo Cox was shot dead outside her office and in 2010 Labour MP Stephen Timms was stabbed at his constituency office.

Jo Cox's husband Brendan said: "Attacking our elected representatives is an attack on democracy itself... there is no excuse, no justification. It is as cowardly as it gets."

Prime Minister Boris Johnson said: "David was a man who believed passionately in this country and in its future and we have lost today a fine public servant and a much loved friend and colleague."

Flags in Downing Street and outside parliament were lowered in tribute.

It is not known what motive there may have been for the killing.

The leader of Plaid Cymru, Adam Price, said Amess was "one of the kindest, most decent and deeply committed politicians I've ever known. It was an honour to call him a friend. My thoughts are with him at this awful time."

Amess was popular with lawmakers and known for his active contributions to debates - often about issues relating to his Essex constituency or animal rights.

In his last contribution to the House of Commons last month, he asked for a debate about animal welfare. 

Carrie Johnson, director of communications at the Aspinall Foundation and wife of the prime minister, called it "devastating news." She added that Amess was "hugely kind and good. An enormous animal lover and true gent. This is so completely unjust. Thoughts are with his wife and their children."

The speaker of the House of Commons, Lindsay Hoyle, said the incident would send shockwaves across the parliamentary community and the whole country, adding that the security of lawmakers would have to discussed.

"Questions are rightly being asked about the safety of our country's elected representatives and I will provide updates in due course," Home Secretary Priti Patel said.

Former Prime MInister Theresa May said: "Heartbreaking to hear of the death of Sir David Amess. A decent man and respected parliamentarian, killed in his own community while carrying out his public duties. A tragic day for our democracy."