Private close protection operatives in the UK cannot be armed. Firearms in the UK are banned and illegal. Therefore no, bodyguards are not allowed to be armed and carry guns in the UK.
Furthermore, it is against the law for civilian close protection operatives to carry any other weapons, including pepper spray, mace, batons, or Tasers.
The same laws apply to international bodyguards visiting the UK from overseas as to CPOs who are UK residents. It is worth noting that visiting close protection teams operating in the UK need to be individually licensed by the SIA (Security Industry Authority), if not they are breaking the law.
The only close protection officers or operatives that are armed in the UK are specially trained police officers employed under Protection Command of the London Metropolitan Police service in the Royalty and Specialist Protection (RaSP). They can legally carry firearms in the UK to protect principals such as Government ministers the Prime Minister, former Prime Ministers, ambassadors, visiting heads of state, and the British Royal Family. They are often referred to as ‘Prot’ or PPOs.
Many unprofessional and inexperienced close protection operatives will fall foul of the law if they believe that they can carry such weapons as knuckle dusters, baseball bats, batons, Tasers, and pepper spray while carrying out their duties. Not only are specific weapons outlawed, carrying anything with the intent of using it as a weapon is also breaking the law. Armed bodyguards are risking their careers, and potentially embarrassing their principal, all for misunderstanding or ignoring their training and the law.
A bodyguard who believes that they can carry weapons in the UK has already failed in their career and has no place within the private security industry.