New MPs have been told to be “on guard” when they answer the door or get into cars amid heightened fears of an attack a year after Jo Cox’s murder.

Politicians were this week told to install fences almost 2 meters high around their houses and locate a place they can hide securely while waiting for police.

They were also urged to agree a “key phrase” with staff that can be uttered during meetings with constituents in case an “emergency” develops.

The chilling advice is contained in a handbook on safety and security issued to all new MPs as they arrived in Parliament after the election.

It is a reflection of the heightened concerns a year after the brutal killing of Ms Cox, the Labour MP for Batley and Spen murdered by a far-Right fanatic.

This weekend a series of events across the country are being carried out to commemorate Ms Cox’s belief that “we have more in common”.