A beaming Princess of Wales poses in front of a Christmas tree in a promotional clip for a “special carol service” at Westminster Abbey.

The service, hosted by Kate, is due to take place at the Gothic abbey in central London on Friday, and will be broadcast on ITV1 and ITVX on Christmas Eve at 7.45pm.

A teaser clip for the Royal Carols: Together At Christmas programme featuring Kate aired on ITV1 at 9.45pm on Thursday.

In it, Kate says: “Join me this Christmas Eve for a special carol service, as we say a heartfelt thank-you to all those supporting the very youngest members of our society during those crucial early years.”

The service, supported by The Royal Foundation, will honour those who work to support babies, young children and families in communities across the UK.

Linked to Kate’s Shaping Us campaign, the service will showcase “the hope of new life and why it is so important to build supportive, nurturing worlds around children and the adults in their lives”.

The Westminster Abbey choir will perform popular carols, alongside musical performances by the likes of Jacob Collier, Freya Ridings and James Bay, and a special duet by Beverley Knight and Adam Lambert.

Prince and Princess of Wales
The Prince of Wales will give a reading during the service (PA)

Readings will be given by speakers including the Prince of Wales, Micheal Ward, Emma Willis, Roman Kemp, and Jim Broadbent, while a specially commissioned poem written by Joseph Coelho, the Children’s Laureate, will be read by Leonie Elliott.

The Christmas Eve broadcast will also feature additional content, including an introduction by Kate and films emphasising the importance of early childhood.

It will include contributions from Rio and Kate Ferdinand, Ugo Monye, Andrea and Virginia Bocelli and Dame Sheila Hancock.

The service will see Westminster Abbey filled with “sustainable, eco-friendly festive decorations”.

New features this year include a Christmas post box located outside the abbey for children to send handmade Christmas cards and best wishes to other youngsters who might be struggling this festive season.

Guests will be treated to carols and Christmas songs upon arrival by the Action for Children Young Carers Aloud choir, made up of 12 young carers including one aged just six.

Attendees have been nominated by lord-lieutenants across the nation, in addition to charities associated with members of the royal family.

They will be joined by those working in early years – a key focus area of Kate’s work through The Royal Foundation Centre for Early Childhood.

The audience will also consist of those who may have had a challenging year, including children and families, or those who might find the winter period difficult.