TfL employees have been told not to stop fare dodgers if it's not safe to do so, after Conservative MP Robert Jenrick filmed himself challenging evaders and even asking one if he was carrying a knife.

It instead trains station staff to assist customers to ensure they pay the right fare and to encourage everyone to tap in and out.

They are advised to leave any situation they judge to be unsafe to TfL's Transport Support and Enforcement officers, who are trained to physically intervene with passengers who fail to comply with travel bylaws.

It is estimated that half of all incidents involving violence or aggression towards TfL staff occur after a fare is dodged.

It comes after the Shadow Justice Secretary yesterday shared a clip of him confronting fare dodgers on the London Underground, asking if one of them was carrying a knife.