Royal couple replacing Meghan Markle and Prince Harry in 'new Fab Four' alongside Kate and Prince William

Stanton pointed to Mike Tindall's appearance on ITV's 'I'm a Celebrity...Get Me Out of Here!' as having a positive influence on the couple's brand.

He said: "Mike and Zara are definitely firm favourites with the public.

"They come across extremely natural and confident within marriage.

"They also aren’t afraid to joke around with each other and show public displays of affection, which comes across as completely relatable.

"I definitely believe Mike’s appearance on I’m A Celebrity has made the public realise that they are very much a normal couple in love.

"This came across as they joined the Royal family on Easter Sunday, as they smiled and joked outside the church.

"I think it’s clear that they’ve got a great dynamic."

He added during his interview with Betfair Casino: "I would probably say that Mike and Zara are clearly enjoying life as part of the new Fab Four, alongside Kate and William."

It comes as a royal commentator claimed Kate found participating in a walkabout with Meghan and Harry "one of the hardest things she has had to do" following the Queen's death.

Robert Jobson, author of a new book titled Our King Charles III: The Man and the Monarch Revealed, claimed that sources told him that while the four royals looked united on the day, it was that not the case.

Jobson said that according to sources, the image of unity was an “illusion”.

He wrote: "Catherine later admitted to a senior royal that, such was the ill feeling between the two couples, the joint walkabout was one of the hardest things she’d ever had to do."