as she continues to prioritise her health following her cancer diagnosis last year. Having completed her treatment last September, Kensington Palace made it clear that she would gradually return to royal duties.

Sources insist that yesterday's last-minute change to the royal guest list was no cause for alarm and that the publication of the first carriage list, which included the Princess, was simply an error, as the Palace had informed the racecourse that she would not be attending.

Aides stressed that there was nothing to worry about, and the decision not to attend the second day of the event comes as she tries to find the right balance in her return to public engagements. Sources added that Kate was "disappointed" not to be there today - having missed the event last year due to her cancer treatment.

The princess, who revealed in January that she is in remission from cancer, was due to arrive in the carriage procession with William, alongside golfer Justin Rose and his wife Kate.

Executives released the list as noon, but Kensington Palace confirmed 20 minutes later that she would not be attending with her husband. She is not expected to attend Royal Ascot any other day this week.

The change meant the procession was altered, with the prince joining the King and Queen in the first carriage alongside Prince Saud bin Khalid Al-Saud of Saudi Arabia's royal family.

The Duke and Duchess of Gloucester rode in the second. The late tweak did not put a dampener on the occasion, with racegoers cheering in temperatures of 27C as the royals arrived.

, beaming in the sunshine in a peach sorbet yellow dress with intricate detailing, a relative snip at £325 from UK brand ME+EM. She completed her look with a blush-toned wide-brimmed hat by Jane Corbett and a cream clutch bag.

As she mixed with the royals, including son-in-law William, Carole covered her mouth with her hand in surprised amusement, and she reached up to stroke the prince's cheek as she listened with concern to what he was telling her.

Other royals in attendance yesterday included the Duke and Duchess of Edinburgh, Princess Anne with Zara and Mike Tindall, Kate's sister-in-law Alizee Middleton - wife of her brother James, - and the Wales's friends Lucy van Straubenzee and Lady Laura Meade.

William presented the trophy to the winner of the Prince of Wales's Stakes - John and Thady Gosden, - trainers of Ombudsman - and jockey William Buick, who later rode the King and Queen's horse Rainbows Edge to seventh in the Kensington Palace Stakes.