Telescope to miss King George VI and Queen Elizabeth Stakes

Telescope, who finished runner-up last year, was due to be ridden by Olivier Peslier for trainer Sir Michael Stoute for the race, in which unbeaten Derby winner Golden Horn is the favourite.

However without going into great detail, a spokesman for owners Highclere Racing said: "Telescope has had a minor setback but should be back on track very soon."

Telescope’s withdrawal is now seen by many observers as paving the way even further for Golden Horn to take out the weekend’s big race.

John Gosden, trainer of the unbeaten three-year-old, believes that the brilliant Derby winner's clash with older horses is "the whole essence" of what the high-summer championship race is all about.

The colt is seeking to build on his successes in the Dante Stakes and Eclipse Stakes as well as at Epsom. But as he attempts to make it six wins from six career starts, Gosden warns he faces probably his biggest test so far.

Gosden, who is twice a King George winner with the three-year-olds Taghrooda in 2014 and Nathaniel in 2011, is likely to also run Eagle Top and Romsdal.

"Golden Horn's been fine since the Eclipse and even progressed physically - he's filled out.

"We always thought that he was a good, proper horse, but he just seems that much more streetwise - harder and tougher now."

However, he added: "These are proper older horses taking him on, four really smart ones. Don't rule the rest out, don't rule the Italian horse Dylan Mouth out."

Golden Horn will be the only member of the Classic-aged generation in a field of up to 10 runners. The field also includes the first three home in Royal Ascot's Hardwicke Stakes - Snow Sky, Eagle Top and Postponed - who are all four-year-olds.

Frankie Dettori will once again take the mount on the son of the stallion Cape Cross, owned by his breeder Anthony Oppenheimer.

Andrea Atzeni will replace Adam Kirby on Postponed in Ascot's midsummer showpiece.

Speculation Kirby had lost the ride was fuelled by his name appearing beside three horses on the advance card for Newmarket on Saturday and Postponed's trainer Luca Cumani confirmed Atzeni would replace him.

"Sheikh Mohammed Obaid has decided to give the ride to Andrea, as he won on the horse last year," Cumani said.

Kirby has ridden the colt on his last three starts, notably a controversial Hardwicke Stakes third to Snow Sky after which John Gosden, trainer of the runner-up Eagle Top, was highly critical of the rider's tactics.

Atzeni was the regular partner of Postponed throughout his three-year-old campaign last season, the pair teaming up to land two valuable races, highlighted by the Group 2 Great Voltigeur Stakes at York where he beat Snow Sky by two and a quarter lengths in the style of a rapidly-improving middle-distance performer.

Postponed has yet to win in three races this year, finishing runner-up to Gosden's Western Hymn in the Group 3 Gordon Richards Stakes at Sandown, third to Al Kazeem in the Group 1 Tattersalls Gold Cup at the Curragh, and then third to Snow Sky at Royal Ascot.

In the latter race Kirby, who became Sheikh Mohammed Obaid Al Maktoum's retained rider when Atzeni signed for Qatar Racing, and Frankie Dettori were involved in a highly-publicised bumping match after both jockeys tried to get an early position just in behind the hot favourite Telescope, who they wanted to track.

Also due in the King George line-up is the highly talented Flintshire, runner-up to Treve in the Prix de l'Arc de Triomphe.