A massive security operation is under way to stop anti-monarchy groups wrecking King Charles’s “second Coronation” next week.
The King will be presented with the oldest Crown Jewels in the UK – the Honours of Scotland – at the ceremony.
But have received intelligence suggesting protesters will try to disrupt the event in Edinburgh on Wednesday.
Police Scotland also deployed anti-terror measures at the weekend.
St Giles’ Cathedral, where the service is taking place, will be closed while officials lift the floor to search for devices.
Meghan Markle 'to unleash her own memoirs' as Prince Harry's drops next weekSections of the Royal Mile, which runs from Edinburgh Castle to the Palace of Holyroodhouse – the monarch’s official Scottish residence –will be cordoned off, nearby roads closed and drones banned.
ACC Tim Mairs said: “Abusive, threatening behaviour or activity intended to disrupt the event that risks public safety is not a legitimate protest.”
Campaign group Republic issued a document that pinpoints protest sites and explains breach of the peace law.
Our Republic, which campaigns for an elected head of state, also said it will hold a rally during the event.
The group said: “As Charles claims the honours he feels entitled to, we will be the reminder that Scotland has never been asked to consent to his rule.”
He will also receive a new sword of state and the ancient Crown of Scotland.
The ceremony will be attended by Queen Camilla and the Prince and
Princess of Wales, known in Scotland as the Duke and Duchess of Rothesay.
At Charles’s insistence, the service will include a psalm sung in Gaelic and passages in the Scots language.
The famed Stone of Destiny is to be moved from Edinburgh Castle to the cathedral for the service, too.
Harry and Meghan convinced 'royals were against them' after New Year photo snubThe King has also turned to his old school for help celebrating the event, with three young pipers from Gordonstoun, in Moray, due to star at the ceremony.
Hamish Martindale, 16, Patrick Blair, 18, and Elspeth Spencer Jones, 18, will pipe when the Scottish Honours arrive at St Giles’.
They will play Scotland The Brave and then Bonnie Lass O Fyvie, after the school was informed that the piece, about a thwarted romance between a soldier and a girl, is a favourite of King Charles.
Thousands of well-wishers are expected to throng Edinburgh’s streets to watch the ‘People’s Procession’ ahead of the service.
The parade, between Edinburgh Castle and St Giles’ Cathedral, will start at 1.15pm and be led by Corporal Cruachan IV, The Royal Regiment of Scotland’s mascot, and supported by cadet musicians.
It will also consist of representatives from charities the Duke of Edinburgh Awards and the Prince’s Trust as well as youngsters from Girlguiding, Scouts and the Boys’ and Girls’ Brigades.
The King will leave Holyroodhouse at 2.05pm as part of a Royal Procession that will head up the Royal Mile.
Republic has ordered its campaigners to ‘direct their energy at that procession and not the People’s Procession’.
The Very Reverend Professor David Fergusson, Dean of His Majesty’s Chapel Royal in Scotland, who will conduct the service at St Giles’, said: “It’s very much a celebration that will involve people from all around Scotland, a service of thanksgiving for what we hold in common and a service of dedication in which we will dedicate ourselves again to the common good of our country.”