LONDON — Forget the Winter Olympics, the Champion’s League or the Super Bowl. The real competition right now is who’s going to be invited to Prince Harry and Meghan Markle’s wedding.

Everyone who is anyone in Britain is angling for an embossed royal ticket.

British heavyweight boxer Anthony Joshua, who is seeking to add two more world championships to the three he already owns, says he would be happy to interrupt his high-level training for a trip to Windsor Castle on May 19. The ebullient Joshua has not been shy, tweeting a picture of himself and Harry with the question “Need a best man?”

“I’m single,” the 28-year-old told the BBC, expressing an interest in seeing if the elegant, raven-haired Markle’s “got any sisters.”

The actual guest list is a closely guarded secret – and details about it may not be released until the event is underway. But that hasn’t stopped speculation about who’s in or out from becoming a national parlor game, and subject of wagers in Britain’s legal betting shops.

Every couple runs into parental interference in their guest list, whether it’s adding random cousins or forgotten neighbors. Yet Harry and Markle are enduring this phenomenon at a cosmic level because of the royal expectations that come along with being a grandson of Queen Elizabeth II.

At least Harry and Markle won’t face the 3,500 guests that his parents, Prince Charles and Lady Diana Spencer, welcomed to their 1981 “wedding of the century” in St. Paul’s Cathedral in London. They also avoided the warehouse-sized Westminster Abbey, where Harry’s brother Prince William and Kate Middleton packed in 1,900 guests for a 2011 royal wedding extravaganza.

Their wedding venue, St. George’s Chapel at Windsor Castle, holds a mere 800 guests. Even so, it’s going to be tough to cut that list. The British royals’ close relatives alone number over 50.