MPs have been advised to share taxis home, amid fears of Brexit-related attacks.
In an email seen by PoliticsHome, deputy Commons speaker Lindsay Hoyle said black cabs had been arranged by the Serjeant at Arms to collect politicians from the House of Commons, and that police had been put on alert over potential threats to MPs.
The warning came after Theresa May revealed she was seeking a three-month extension to Article 50 earlier this week.
In his email, Mr Hoyle wrote that he had "never felt this level of tension" during his time in the Commons.
"The public is looking to us to resolve the current impasse and it is clear that tensions and emotions are running at an all-time high," he wrote.
"Personally, I have never felt this level of tension during my time in the House and I am aware that other colleagues feel the same. Many colleagues have already been subject to widely publicised abuse and intimidation.
"I want to reassure you that measures are in place to allow Members - and our staff - to do our jobs safely."
He continued: "We can also take simple steps to improve our personal safety by travelling home from the House by taxi or with colleagues in the coming days."