A man has admitted trying to harm Britain's Queen Elizabeth after being caught in the grounds of Windsor Castle with a loaded crossbow in 2021.

Jaswant Singh Chail, 21, pleaded guilty to three charges, including an offence under the Treason Act, during a hearing at the Old Bailey.

The most serious charge under Section Two of the Treason Act said that "on December 25 2021 at Windsor Castle, near to the person of the Queen, you did wilfully produce or have a loaded crossbow with intent to use the same to injure the person of Her Majesty Queen Elizabeth the Second, or to alarm her Majesty".

He was also charged with making a threat to kill the queen and having a loaded crossbow, an offensive weapon, in a public place.

The defendant had been detained on Christmas Day, 2021 close to the queen's private residence, where she was at the time.

The late Queen Elizabeth II

Chail, who was unemployed at the time but previously worked for a branch of the Co-op supermarket, was spotted in the grounds of Windsor Castle at about 8.10am.

It is understood he had scaled the perimeter of the grounds with a nylon rope ladder some two hours before.

He was said to be wearing a hood and mask and was carrying a crossbow loaded with a bolt, with the safety catch off and ready to fire.

He told a police protection officer "I am here to kill the queen", before he was handcuffed and arrested.

It was alleged that Chail had previously applied to join the Ministry of Defence Police and the Grenadier Guards, in a bid to get close to the royal family.

Prosecutors allege he sought revenge against the establishment for the treatment of Indians, and had sent a video to about 20 people claiming he was going to attempt to assassinate the queen.

The Supersonic X-Bow weapon he was carrying had the potential to cause "serious or fatal injuries", according to the prosecution.

Chail, from Southampton, Hampshire, entered his guilty pleas before senior judge Mr Justice Jeremy Baker by video link from Broadmoor hospital.

The allegations were not being treated as a terrorism offence but had been dealt with by the Counter-Terrorism Division.