Champion jockey Richard Hughes has been booked to ride Australia's July Cup contender Shamexpress in the Group One sprint at Newmarket on Saturday week.

Hughes replaces Craig Newitt who has opted not to return to England for the race.

Newitt won the Newmarket Handicap at Flemington on the Danny O'Brien-trained colt and was aboard when Shamexpress finished ninth in the King's Stand at Royal Ascot.

He said had Shamexpress figured in the finish he would have gone back to England to ride him again.

Hughes rode his 100th winner for the season on Monday and is the raging favourite to retain his champion title.

His Group One wins this year include the Coronation Stakes at Royal Ascot on Sky Lantern.