Westminster Abbey will be turned into a fortress to guard the Crown Jewels from an audacious Coronation heist.
The massive top-secret exercise, which is dubbed Operation Tower of London, involves thousands of police manning London’s streets.
It will be backed up by elite teams of armed guards, snipers and the military.
Dozens of undercover officers will mix with the crowds as the King and Queen Consort travel to and from Buckingham Palace.
A source said: “The operation is huge, certainly in a similar scale to that of the funeral of the Queen, the largest event in a generation.
“Every available arm of the police and security services has been dispatched.
“The exercise turns the Abbey into Operation Tower of London, focussing on maximum security and maximum lockdown.”
The operation is headed by a joint task force consisting of a Met Police Gold Commander and MI5.
It will effectively turn the Abbey into the Tower of London in terms of security for Coronation regalia that never leaves the castle.
It can be revealed the King and Camilla have been rehearsing with replicas of the jewelled crowns, staffs and swords, created ahead of King George VI’s coronation in 1937.
The couple also presented new Standards and Colours to the military at the Palace yesterday.
They will also on show at next week’s Coronation.
Elsewhere, an operation is under way to move the Stone of Destiny from Edinburgh to the Abbey.
It will be its first trip to England since it was officially returned to Scotland after 700 years by then PM John Major in 1996.
The Stone of Scone was removed by King Edward I of England in 1296. It will be moved under tight security, following a raid in 1950, before being placed under the Coronation Chair.
Sources also revealed concerns over protesters plotting to disrupt the ceremony, including rape alarms being hurled at horses.
Cabinet Office minister Oliver Dowden said he has received intelligence reports about potential disruption, adding: “We take this very seriously. I have been meeting with the Home Secretary, with the Culture Secretary, who has responsibility for the ceremonials.”
The Mirror can reveal jamming technology to block drones from flying near the Coronation will be used next Saturday.
The Civil Aviation Authority has imposed a “no-fly zone” over Central London amid concerns terrorists or protestors could target the event.
Counter-drone radar units will be set up on the procession route along with devices to block signals between pilots on the ground and their aircraft.
Thousands of uniformed officers will line the one-mile route between the Palace and Westminster Cathedral.
There will be armed officers on streets and snipers on rooftops, while small numbers of SAS and Special Reconnaissance Regiment troops will scan for security risks.
Rooftop teams with high-powered binoculars will help spot trouble-makers and terror threats.
Elite troops in plain clothes will look for “lone-wolf” attackers”.
During an attack the SAS will fly in on “Blue Thunder” Dauphin 2 unmarked helicopters.
Helicopters and police drones will help monitor crowds.
Motorbike escort riders, the Met’s horse-mounted branch, dog teams and a marine unit will be used.
Counter-terrorist specialist firearms Officers, dubbed Robocops, will be deployed along with fast response units on motorbikes.
A source said: “There will be a special forces presence but it will be very low-key.”
Meanwhile, an Official Album of the Coronation will be available to download on May 6.
The historic recording, featuring music and spoken word from the ceremony, will aid the Royal British Legion and Age UK.
