Barnsley MP Dan Jarvis joined fellow MPs from across the county in warning of the rising tide of intimidation against elected politicians.
He revealed that a death threat had been made against him, and that he had been forced to move his constituency office to protect his staff.
Mr Jarvis’s intervention comes after a number of recent incidents involving the region’s politicians, which required police action.
Last month a man was given a conditional caution after threatening Normanton, Pontefract and Castleford MP Yvette Cooper.
It follows an earlier revelation from Dewsbury MP Paula Sherriff who claimed that swastikas had been left outside her constituency office.
This comes as the latest official figures show a huge increase in spending on MPs’ security over the past two years, from £170,000 in 2015/16 to £4.2m last year.
Other MPs who have also been targeted include Labour’s Mary Creagh and Rachel Reeves and Tory MP for Morley and Outwood MP Andrea Jenkyns.
All three women raised concerns over the level of harassment they receive and said they had been forced to be more discreet about their constituency work amid safety fears.
In speaking about his own experience, Mr Jarvis said he hoped to show support for colleagues and pave the way for better protection, particularly online.
In a letter - sent during the 2017 General Election and seen by The Yorkshire Post - the unnamed author told the ex-Army Major he had procured a gun and would kill him if he remained in political office.
He said: “I was obviously concerned about where that letter had come from and whether there was a risk that we would knock on the door of that person, because we didn’t know who they were.”
Politicians across the country ramped up security measures in the wake of the murder of Batley and Spen MP Jo Cox in 2016, but Mr Jarvis said the memory of that tragic day still weighs heavy.
“All of us are still haunted by what happened to Jo,” he said.
In light of the threats made against him and his colleagues, as well as the barrage of low-level abuse many MPs get on a regular basis, Mr Jarvis warned that good people would be forced out of politics
He said: “I worry that people will leave because they just don’t think it’s worth it.
“And I worry that good people that would be excellent representatives won’t come and do it in the first place.”