|Prince Charles (top) and Camilla
London, March 13: The police are to stage an unprecedented security operation to prevent the wedding of the Prince of Wales and Camilla Parker Bowles from being infiltrated by terrorists and protesters.
At least one anarchist group, Movement Against the Monarchy (Ma'm), plans to disrupt the proceedings and organisers hope that 500 protesters will descend on Windsor on April 8.
The anarchist group has announced two days of protests on its website.
It says: 'Having driven his first wife to numerous suicide attempts, Prince Charles announces plans to marry his mistress on April 8, 2005. A great chance for anti-royal activity.
'A good-humoured set of demonstrations are planned for Saturday, April 2 and Friday, April 8 in Windsor.'
It gives an email address and mobile telephone number for those wanting details.
Ma'm is the best-known and most organised of the anti-monarchy groups. It is believed to have formed in the 1990s and has targeted several royal celebrations. It held several demonstrations during the Queen's Golden Jubilee year in 2002, and targeted celebrations to mark the Queen Mother's 100th birthday. Critics say that it is a spiteful group.
Detectives from Thames Valley Police and the Metropolitan Police are monitoring the websites of Ma'm and other protest groups in an attempt to prevent demonstrators ruining the day.
The two police forces are staging a joint security operation and Peter Neyroud, the chief constable of Thames Valley Police, and Sir Ian Blair, the Metropolitan Police commissioner, have made it clear that there must be no repeat of the security lapse that allowed Aaron Barschak, the 'comedy terrorist', to gatecrash Prince William's 21st birthday party at Windsor Castle in 2003.
Top officers say privately that the need to move the civil ceremony from Windsor Castle to the Guildhall nearby has made their job more difficult.
They will need to check the route for explosives and protect the couple and their guests as they move from the Guildhall to Windsor Castle for the dedication from Dr Rowan Williams, the Archbishop of Canterbury.
At least 200 officers will patrol the streets of Windsor and the castle. Officers are being drafted in from Berkshire, Oxfordshire and Buckinghamshire for the occasion. It is expected that police snipers will be positioned on roof tops and undercover officers will mingle with the crowds.
A police spokesman said: 'Security will involve a joint operation by Thames Valley Police, the Metropolitan Police and Windsor and Maidenhead borough council.'
Police will limit the area where protesters can demonstrate and keep them away from the couple.
The Metropolitan Police's diplomatic protection squad is responsible for the security of members of the Royal Family and the royal homes, including Windsor Castle. Thames Valley police is responsible for security at the Guildhall and on the streets of Windsor.
Supporters and friends of the late Diana, Princess of Wales, are not expected to protest in Windsor on April 8.
Joan Berry, 60, a founding member of the Diana Circle, a group dedicated to keeping memory of the Princess alive, said it would advise members to visit Kensington Palace to pay their respects or display pictures of the Princess in their front windows.