Intimidation and threats to MPs are at unprecedented levels, according to the House of Commons Speaker.
Alongside physical threats, parliamentarians are facing constant cyber-attacks from "foreign actors" trying to "disrupt" the work of the Commons, Sir Lindsay Hoyle said.
Sir Lindsay, who is responsible for MPs' welfare, said improving security in the House of Commons was "the top priority" over the next five years.
In his first interview since being re-elected as speaker, he told OceanNewsUK he had "never seen anything as bad" as the current level of intimidation against MPs.
Sir Lindsay saw the Commons descend into acrimony in February when he broke convention to permit a vote on Labour's Gaza ceasefire motion.
At the time, he said he had allowed the vote to protect MPs' safety.
Asked about how he plans to protect MPs, he said: “I’ve got to be honest, the amount of intimidation and threats and the way it’s carried out, is much greater than anybody can imagine.
“People must be allowed to vote without intimidation.
“Democracy matters to me. That is a constant worry. If there’s something that keeps me awake at night, it is the safety of MPs.”
He added: “Cyber-attacks are continuous from foreign actors. The staff have been fantastic in fighting foreign actors trying to disrupt Parliament.
“None of this should happen, so I work very closely with all the agencies to make sure we are on top of our game."
The last parliament had a cloud of misconduct hanging over it with suspensions of MPs, lobbying scandals and bullying allegations.
Behaviour in Parliament also needs to improve, according to Sir Lindsay.
He sees this new parliament as a fresh start and all parties needed to "swing" behind efforts to improve standards to create a "better" and "nicer Parliament".
"How we treat each other in Parliament is reflected by the public," he said.
Asked about holding the government to account in light of Labour's 172-seat majority, Sir Lindsay said he would "fall out" with Prime Minister Keir Starmer if key announcements bypassed Commons scrutiny.
He said he had been given an "assurance" that when the Commons is sitting "major announcements will be made on the floor of the House".
Sir Lindsay won a landslide victory of his own, after being re-elected unopposed by MPs in the traditional speaker's election at the start of the new parliament.
He promised to protect the rights of smaller parties, ensuring they get a fair chance to speak.
Sir Lindsay also signalled his support for Labour's plans to modernise the Commons, forming a committee to review parliamentary procedures.
"Modernisation is good," he said.
“It’s about keeping tradition, but moving into a modern way of delivering," he added.
