Prince Archie and Princess Lilibet may be given roles in King Charles' coronation - if their parents confirm their attendance

However, it has now emerged that two sets of plans are being drawn up, which depend on whether the king's youngest son Prince Harry, and his wife Meghan, Duchess of Sussex, will be in attendance along with their children Archie, who turns four on coronation day, and 21-month-old Lilibet.

A source told the Mail on Sunday newspaper: "Two versions of the plans [for the day] are being drawn up. One includes Harry and Meghan and one doesn't. Timings are all approximate at this stage, but they are working towards a timetable now."

It was previously revealed Prince William and his wife Catherine will be joined in a carriage behind Charles and his wife, Queen Consort Camilla, by their three children.

The procession will also include the Princess Royal, her husband Vice Admiral Sir Tim Laurence, the Duke and Duchess of Edinburgh, the Duke and Duchess of Gloucester and Duke of Kent and Princess Alexandra, according to The Times newspaper.

As well as the Sussexes not being seen in the draft documents, the plans also showed no roles for Prince Andrew or his daughters Princess Beatrice and Princess Eugenie.

Charles' coronation will fall on a Saturday and the following day, Windsor Castle is set to host a concert that will be broadcast around the world, with thousands of street parties in the afternoon across the UK.

It will be followed by a Bank Holiday on Monday, May 8, which will give millions of people a day off work.

The ceremony will start with Camilla being crowned, before Charles is officially made monarch by the St Edward's Crown being placed on his head by the Archbishop of Canterbury.

A procession will lead the king - who is to be anointed with vegan holy oil - past thousands of people to Buckingham Palace, where he will join members of the royal family on the balcony to wave at fans.

The plans follow reports last year Charles was intent on having a "slimmed down" coronation compared to his late mother's, when 8,251 people squeezed into Westminster Abbey to mark her ascension to the throne.