Mike Freer, who has served as the MP for Finchley and Golders Green since 2010, told the Politics Hub With Sophy Ridge he had reached the moment where "the level of risk becomes too much".

He also said the impact on his family "when they see you going out to do some part of your job in a stab vest" was "really not fair on them".

Politics live: Labour MP details almost 50 years of death threats

The Tory MP also called for action from social media companies to "get to the root cause" of the problem, saying people are "being given the green light to feel they have got open season on their public servants" through the platforms.

Mr Freer announced his plan to leave the Commons on Wednesday, saying an arson attack on his constituency office in north London on Christmas Eve was "the last straw".

But it was the latest in a string of incidents - including what he described as a "narrow miss" with the killer of his colleague, Southend MP Sir David Amess.

"The man who went on to kill Sir David came to Finchley first," said Mr Freer.

"And it was purely a fluke that I had been reshuffled into a different position by Boris [Johnson], and I ended up being in Westminster and not in Finchley [that day].

"Otherwise I suspect I would have been attacked, because he did say he would come to Finchley armed and with intent to harm."

'The last straw'

Mr Freer added: "Every MP has to cope with a level of abuse and a lot of it low level, whether it is graffiti, rude emails or someone shouting at you. That's almost par for the course these days.

"But once you've had two or three threats to your life - that was bad enough and certainly gave me pause to think - and then after I had a narrow miss... then the arson attack was just the last straw."

The Tory MP said the "difficulty" with facing such abuse and threats was "you never know what could happen next".

He described "run-ins" he had with the banned Islamist radical group Muslims Against Crusades - including when some of its members broke into his office and protested outside.

"Our offices have often been turned into fortresses now, our homes are turned into fortresses," Mr Freer added.

"But we are at risk when we are walking the street, when we are going to the shop, when we are trying to do so much of our daily constituency work.

"That's where the risk is the greatest and you are just never quite sure what's around the corner."

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While the minister said he welcomed additional security support for MPs, he said it was not "addressing the point".

"One of my biggest concerns is social media especially, it has a lot to answer for," said the MP. "It allows and it gives free rein to people to be aggressive, to say what they want, and with little consequence.

"If you complain to social media, nothing seems to happen and that's the bit we need to address - not just give more and more security, but actually stop people either being radicalised or being given the green light to feel they have got open season on their public services."

'Immediate, horrific and awful'

Also speaking to Sophy Ridge on Thursday was Labour stalwart Dame Margaret Hodge, who revealed she was subject to her first death threat as a politician in 1976 when she was a local councillor.

"There was a man with an axe who was threatening me," she said. "So it's always come a little bit with the territory."

She also revealed she was "on the list" of an attacker who stabbed Labour MP Stephen Timms back in 2010, and had received a death threat as recently as today.

Speaking about Mr Freer's decision to stand down, Dame Margaret said: "It's depressing, it's shocking, but it's unsurprising if you have faced the sort of threats that he's faced. You can understand why he's put his family first."

She also expressed agreement over issues surrounding social media, adding: "I think back to my time fighting to be an MP up to the election in 2010, which was a pretty vicious campaign.

"But there was no social media so it was the phone, it was letters and it was emails. It was easier to control.

"It's social media that has made it so immediate, so horrific and so awful."

The Labour MP said she believed "there are things we can do about it" - including stopping people from posting anonymously on platforms. But she added: "It's just there has to be a will to do that."