Royal wedding: Military rehearsal takes place
A pre-dawn military walk-through of the royal wedding route has taken place, ahead of Prince William's marriage to Kate Middleton in London on Friday.
Up to 1,000 members of the Army, Royal Navy and RAF left Wellington Barracks in Westminster shortly before 0500 BST.
Carriages took part in the full-scale procession to Westminster Abbey, along with two royal fleet cars.
Later Prince William and Kate Middleton attended a private wedding rehearsal at Westminster Abbey.
David Cameron sent his best wishes to the couple during prime minister's questions in the Commons.
He told MPs the "whole world" was looking forward to the ceremony.
"I'm sure the whole House will want to join me in sending our best wishes to Prince William and Catherine Middleton ahead of their wedding this Friday and to wish them a long and happy life together."
The Archbishop of York John Sentamu, meanwhile, said the royal wedding would "inject a bit of hope" into Britain as people struggled in financially tough times.
During the pre-dawn practice, soldiers lined the route to the Cenotaph, outside the entrance to Downing Street.
From there, the RAF lined the road to Horse Guards Parade, members of the Army lined Parliament Street and several companies of the Royal Navy lined the conclusion of the route.
The abbey closed its doors to the public on Tuesday so that preparations could get under way.
On Friday the carriage procession will pass along The Mall, Horse Guards Road, Horse Guards Parade, through Horse Guards Arch, along Whitehall, along the south side of Parliament Square and into Broad Sanctuary.
A dress rehearsal for clergy and broadcasters is also scheduled for Wednesday, while the royal couple are expected to hold their own preparations with senior clergy at the abbey.
Pilots taking part in a flypast to mark the celebrations have also been rehearsing out of RAF Coningsby in Lincolnshire.
Seven aircraft will take part in the formation that will fly over Buckingham Palace, including a Spitfire, Hurricane and a Lancaster in the Battle of Britain Memorial Flight formation, followed 32 seconds later by two Tornado planes and two Typhoons in the Windsor formation.
Meanwhile, members of the public have begun camping out in front of the abbey.
John Loughrey, 56, who began his week-long vigil on Monday night, said he planned to stay in his position to ensure a prime spot for the event.
Faith Nicholson, 49, from east London, flew back from a Spanish holiday to join the crowds outside the abbey.
She said: "I'm here for the atmosphere, not just for the event. I'll stay here if it rains. I don't have an umbrella or anything, I really don't care. I just want a good view of William and Kate."
As well as the Royal Family, 50 heads of state are attending the ceremony, which it is anticipated will be watched by up to two billion people on television. There will be 70-80 close protection teams for VIPs on the day.
On Tuesday, detectives leading the major royal wedding security operation appealed for the public to be the "eyes and ears" of the 5,000 officers tasked with maintaining law and order on the big day.
Scotland Yard's appeal came alongside a warning that anyone attempting to disrupt the wedding in central London on Friday would face a "robust" response.
The Islamist group Muslims against Crusades told reporters on Wednesday it had dropped plans to protest after its application for an event outside Westminster Abbey was rejected.
Nationalist group the English Defence League had threatened to hold a counter-demonstration if the police granted permission to Muslims against Crusades. It has since said that no counter-protest will be held.
Elsewhere, a separate protest group with Middle Eastern links has warned police it is planning disruptions.
Police have powers to ban any major protests along the main route that the royal couple will take but are unable to rule out "static" protests taking place at other nearby locations.