It is technically illegal to wear armour in the British Parliament
The Statute Forbidding Bearing of Armour, passed in 1313, prohibits wearing armour in Parliament. The law was passed in the reign of Edward II and was intended to prevent armed factions from intimidating the proceedings. It has never been formally repealed. The same statute that bans armour in Parliament has coexisted with modern metal detectors and security procedures for seven centuries without anyone noticing it might need an update. Technically, every security guard wearing a bulletproof vest in Parliament is in breach of a 700-year-old law.
A 700-year-old law against bringing weapons to Parliament is still technically valid — which means every security guard wearing body armour inside Westminster is breaking the Statute of Edward II.
“It's illegal to wear armour in the British Parliament — under a 1313 law that has never been repealed. Security guards break it daily.”