The royal security breach raises questions about the Metropolitan Police which must be investigated by a full independent inquiry, an MP said today.
Tory backbencher Mark Pritchard insisted last night's incident involving the Prince of Wales and Duchess of Cornwall could not be left to an internal Scotland Yard investigation.
Prime Minister David Cameron has said he is "very concerned" about the "very regrettable" security lapse and that Met Commissioner Sir Paul Stephenson would report on it.
But Mr Pritchard called for an independent inquiry, possibly led by a retired high court judge.
"This was an incident that was so very serious - and could have been even more serious - that it should not be left to an internal Metropolitan Police inquiry," he said.
"There needs to be an independent inquiry, given the many questions that need to be answered about why the royals took that route."
The MP questioned how many minutes in advance of Charles and Camilla's journey was their route checked and who by, and suggested that could be verified by CCTV footage.
"While I applaud the professionalism and bravery of the frontline police officers protecting the royals, there are serious questions to be asked at the most senior levels of the Metropolitan Police about why they were allowed to take that route," Mr Pritchard said.
"It's not rocket science to know that that part of London would at least be chock-a-block with displaced traffic."
The Prime Minister's official spokesman said earlier that Downing Street had "full confidence" in the police.
Asked why Sir Paul was the best person to look into the incident, the spokesman said: "Because he's responsible for the police.
"I think the police are best placed to make judgments on these operational issues."
A spokesman for the Prince of Wales and Duchess of Cornwall said the royal couple "totally understand the difficulties which the police face" and are "always very grateful to the police" for the job they do.
How Charles was caught in protest
This is a timetable of how the Prince of Wales and the Duchess of Cornwall became caught up in the shocking violent protests on the streets of London.
All timings are approximate and some precise details of the route are unclear.
* 7.10pm - Charles and Camilla set off from their Clarence House home, next to St James's Park in central London, to attend the Royal Variety Performance at the London Palladium. Their Rolls-Royce limousine is part of a convoy flanked by police outriders on motorcycles. The royal party heads up St James Street, then turns right into Piccadilly.
* 7.15pm - Charles and Camilla's car turns left into Regent Street at Piccadilly Circus, one of the busiest road junctions in the capital. Shortly afterwards the Rolls-Royce is surrounded by angry protesters, who smash one of the rear side windows and pelt it with paint.
* 7.20pm - The convoy turns right into Argyll Street and parks outside the London Palladium. The Prince and the Duchess of Cornwall emerge looking shaken.
* 10.50pm - Camilla laughs off the attack as she emerges after the show. Asked how she is as she leaves the theatre, the Duchess says: "I'm fine thanks - first time for everything." Following behind, Charles smiles as the couple get into the back of a marked police van which takes them away.Reuse content