Trainer Ed Walker’s bid to win his first Group 1 race with stable star Starman in Saturday’s Diamond Jubilee Stakes (1200m) is threatened by rain.

Favourite on the run up to the day’s feature event, the lightly-raced Starman’s prospects could be damaged by rain while those of leading rival Dream Of Dreams have improved.

Walker is confident of Starman’s ability to land the big prize but concerned at the impact of softening ground. He reported: “Starman is a massively exciting horse, big and imposing, magnificent to be around. He’s got presence, a real head turner and very good as well. We are really happy with him and so far everything has gone well since his win at York last month.”

While Walker is happy with his stable star he is less pleased with the weather forecast. “Good, honest fast summer ground would be in our favour,” he said. “Starman’s able to show his turn of foot on a fast surface. When he was disappointing in last year’s Champions Sprint Stakes at Ascot the ground was shocking and we put a line through that.”

The ground was faster for Starman’s seasonal debut in a G2 event at York. Walker remarked: “We thought he might have needed the race slightly but he won very nicely. What he’s done already is hugely exciting. He goes to Ascot as the one to beat.”

While Walker looks anxiously at the dark sky, it holds no fears for Sir Michael Stoute. His seven-year-old Dream Of Dreams would be a deserved winner, having been beaten a head in this race in both 2019 and 2020. Dream Of Dreams acts on fast going but is better with give in the ground.

Stoute said: “Twice the winning post has come just too soon. We’re hoping for a change of luck. He looks in good shape physically and mentally and I’m sure he’ll be competitive again. There’s no reason why he shouldn’t run as well as he has done before.”

Walker was surprised Nahaarr got as close as he did to Starman in the Duke Of York Stakes (1200m) at York last month but it gave trainer William Haggas confidence. His belief in Nahaarr’s improvement and toughness – the five-year-old was having his first run at Group level at York – is indicated by having considered running him twice at the meeting.

Haggas said: “If the ground had been less fast for the King’s Stand Stakes on Tuesday, we might have run him in that and in the Diamond Jubilee. As it is, we’ve decided to wait for Saturday. He is very tough and looks absolutely fantastic, he’s ready to go.”

While Nahaarr’s preparation has gone smoothly, that of Royal Commando, fourth at Royal Ascot last year in the G1 Commonwealth Cup (1200m) and winner of the Listed Cammidge Trophy Stakes (1202m) at Doncaster in March, has been less straightforward. Trainer Charlie Hills explained: “Ideally, we wanted to give him another run before Ascot. He was going to run in Ireland but heavy ground and Covid got in the way. He’s got to improve to win.”