William, Kate will represent King Charles amid rumors about Christmas Lunch

People are already speculating whether Kate Middleton will wear an old dress or opt for a new one when she joins her husband, Prince William, to receive foreign guests on behalf of King Charles.

According to local media, German President Frank-Walter Steinmeier and his wife, Elke Budenbender, will be formally welcomed by the Prince and Princess of Wales at Heathrow tomorrow before traveling to Windsor.

King Charles will host the German president for the historic state visit in Windsor, marking the third major state visit this year.

According to Mirror, "After a carriage ride through the streets to the castle, Steinmeier will receive a ceremonial welcome in the castle quadrangle, attended by the King, Camilla, William, and Kate."

The German president will then be feted with a grand state banquet in the historic royal residence's St George's Hall on Wednesday evening.

On Thursday morning, he will privately lay flowers at the tomb of the late Queen Elizabeth II in the castle's St George's Chapel, before joining the King and Queen for a Big Help Out reception to showcase the impact volunteering can have on communities.

As news of William and Kate's rare joint appearance surfaced online, royal fans started speculating about the brands Princess Kate will choose for the occasion.

While names of many designers were mentioned on social media, some people were convinced that the future queen might wear a German designer, a choice befitting for the occasion.

William and Kate will be representing the monarch at a time when speculation is rife that they plan to skip King Charles's private Christmas lunch amid ongoing tensions within the royal family.

But their appearance together to represent King Charles at the airport contradicts claims made by some royal observers.

While it's not known whether they will skip the event, it appears that even if they choose not to attend the lunch, it won't necessarily be due to alleged differences within the royal family.