The force said in a statement: “At around 17.23 hrs, a man approached the gates of Buckingham Palace and handcuffed himself to them.

“Officers in the area immediately approached the man, believed aged in his 30s, who began threatening to harm himself.

“London Ambulance Service are also on scene. Police are trying to speak to the man and bring the situation to a swift conclusion to ensure his safety and welfare.”

No members of the Royal family are currently in residence at the Palace as it is undergoing a major refurbishment programme not due to be completed until 2027.