Millions watching King Charles' coronation around the world will be asked to cry out and swear allegiance to the monarch, with the public given an active role in the ancient ceremony for the first time.
Charles's coronation on May 6 has been modernised to include the first ever Homage of the People.
The office of the Archbishop of Canterbury, Lambeth Palace, said it was hoped the significant change to the historic service will result in a "great cry around the nation and around the world of support for the King" from those watching on television, online or gathered in the open air at big screens.
It replaces the traditional Homage of Peers in which a long line of hereditary peers knelt and made a pledge to the monarch in person.
The new Homage of the People was introduced to allow "a chorus of millions of voices" to be "enabled for the first time in history to participate in this solemn and joyful moment", Lambeth Palace said.
The Archbishop will call upon "all persons of goodwill in The United Kingdom of Great Britain and Northern Ireland, and of the other Realms and the Territories to make their homage, in heart and voice, to their undoubted King, defender of all".
The order of service will read: "All who so desire, in the Abbey, and elsewhere, say together:
"All: I swear that I will pay true allegiance to Your Majesty, and to your heirs and successors according to law. So help me God."
It will be followed by the playing of a fanfare.
The Archbishop of Canterbury will then proclaim "God save the King", with all asked to respond: "God save King Charles. Long live King Charles. May the King live for ever."
A spokesman for Lambeth Palace said technology made it possible for people watching the Westminster Abbey ceremony around the world to pay homage to the King.
"Our hope is at that point, when the Archbishop invites people to join in, that people wherever they are, if they're watching at home on their own, watching the telly, will say it out loud - this sense of a great cry around the nation and around the world of support for the King," the spokesman said.
Before the Homage of the People, Prince William will perform the Homage of Royal Blood.
William will kneel before the monarch, place his hands between his father's and vow to be his "liege man of life and limb".
The symbolic act means the heir to throne, as 'liege man' to the King, has a mutual obligation to the monarch.
In the past, other dukes of royal blood would pay homage, but this time, with only William taking part from the royal family, it removes the need for the controversial Prince Harry and Prince Andrew to undertake the role.
Australian Associated Press
