The British Prime Minister struggled with an umbrella in inclement weather during a dedication ceremony for a new police memorial in the English county of Staffordshire.
In footage aired by UK broadcaster Sky, Boris Johnson's umbrella turns inside out in the pouring rain, as he was sat next to Prince Charles at the ceremony.
The prince appeared amused at the ordeal, laughing at his misfortune but not providing assistance.
The event was to recognise the sacrifice of police officers who had died on duty.
New Zealand-born policeman Matiu (Matt) Ratana was shot and killed while working at Croydon custody centre on September 25 last year.