Princess Eugenie is counting down the hours to her lavish royal wedding.

The Queen’s grand-daughter has just one day to go until she says her marriage vows to tequila brand ambassador Jack Brooksbank in the gothic surrounds of St George’s Chapel, Windsor Castle.

Some 850 guests will gather in the historic surroundings where the Duke and Duchess of Sussex wed five months ago.

Harry and Meghan and the Duke and Duchess of Cambridge are expected to be among the guests on Friday, along with the Queen and a host of royals.

The Duke and Duchess of Sussex first official visit to Sussex
Harry and Meghan are expected to attend (Daniel Leal-Olivas/PA)

Celebrity guests will include former Take That singer Robbie Williams and his wife and fellow X Factor judge Ayda Field.

Williams’ six-year-old daughter Theodora is taking a starring role as a bridesmaid, alongside five-year-old Prince George and three-year-old Princess Charlotte.

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George and Charlotte will be among the pageboys and bridesmaids (Jane Barlow/PA)

Royal fans will be hoping for some fun-filled antics from the young helpers in the bridal party, which include Zara and Mike Tindall’s spirited four-year-old Mia and Peter and Autumn Phillips’ daughters Savannah and Isla.

Maud Windsor, who is Eugenie’s goddaughter and the daughter of Lord Frederick Windsor and his actress wife Sophie Winkleman, is also a bridesmaid.

Future king George will be joined by fellow page boy Louis de Givenchy – the six-year-old son of JP Morgan banking executive Olivier de Givenchy and his wife Zoe.

The Queen’s youngest grandchildren, 14-year-old Lady Louise Mountbatten-Windsor and 10-year-old Viscount Severn, who are the children of the Earl and Countess of Wessex, will take on the role of Special Attendants.

William and Kate’s youngest child Prince Louis, who is only five and a half months old, is too young to attend and will be staying at home.

The Duchess of Cornwall will also be missing, having a long-standing engagement at a school in Scotland.

Proud parents the Duke of York and Sarah, Duchess of York will be gearing up for the celebrations.

Andrew has remained on very friendly terms with his ex-wife the duchess amid speculation they might even remarry.

However, her relationship with her former father-in-law the Duke of Edinburgh is said to be non-existent.

Horse Racing – The Royal Ascot Meeting 2015 – Day Four – Ascot Racecourse
The Yorks at Ascot (Steve Parsons/PA)

Philip is said to have never forgiven “Fergie” for the scandal she caused when she was caught in the infamous “toe-sucking” incident, having her feet kissed by financial adviser John Bryan in 1992.

The groom Jack has asked his brother Thomas to be his best man while Eugenie’s older sister Princess Beatrice will be her maid of honour.

Stars predicted to attend the second royal wedding of the year include singer Ellie Goulding and fiance Caspar Jopling, supermodel Cindy Crawford, David and Victoria Beckham, Harry’s exes Cressida Bonas and Chelsy Davy, model Cara Delevingne, singer James Blunt and wife Sofia Wellesley, and George and Amal Clooney.

Wimbledon 2017 – Day Eight – The All England Lawn Tennis and Croquet Club
Ellie Goulding is expected to be among the celebrities attending (Adam Davy/PA)

Jack works as a drinks executive for Casamigos tequila, which was founded by Clooney and Crawford’s husband Rande Gerber.

Italian singer-songwriter Andrea Bocelli will perform two pieces during the ceremony which begins at 11am, with members of the Royal Philharmonic Orchestra also featuring.

The wedding service will include a personal prayer written by Archbishop of York John Sentamu.

Dean of Windsor David Conner will give the address and also officiate as the couple make their marriage vows.

The Queen is hosting an afternoon reception afterwards in the castle’s St George’s Hall, but the festivities are expected to continue into the early hours with an evening party at the York family home, the Royal Lodge in Windsor Great Park.

Royals fans hoping to catch a glimpse of the bride can wait for the newlyweds’ carriage procession through Windsor town centre – but the couple will not be travelling up the Long Walk to the Castle like Harry and Meghan did.

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No Long Walk carriage procession route for Eugenie and Jack (Yui Mok/PA)

About 1,200 members of the public have been given balloted invites to the castle’s Lower Ward, as have charity representatives, children from Eugenie’s old schools, and royal household staff.

Republic, a campaigning group working for an elected head of state, has criticised the security cost to the taxpayer, saying estimates have put the bill at £2 million.

Eugenie is ninth in line to the throne.

The wedding is being screened in full on ITV as part of a special three-hour This Morning show live from Windsor, hosted by Eamonn Holmes and Ruth Langsford.

Broadcast footage will also be live streamed on The Royal Channel and The Duke of York’s YouTube channels, and the royal family and Andrew’s Facebook pages.