Mohaather may be the one to beat in Goodwood's Sussex Stakes

The Group 1 mile showpiece, which forms part of the QIPCO British Champions Series, has attracted Kameko and Wichita, who dominated the finish of the QIPCO 2000 Guineas last month, plus Siskin and Vatican City, who were the first two home in the Tattersalls Irish 2000 Guineas.

The Classic generation will be challenged by Circus Maximus, a three-time Group 1 winner who was runner-up to Too Darn Hot in last year’s Sussex Stakes, plus Mohaather and San Donato, the first two home in the Group 2 Betfred Summer Mile at Ascot this month.

Mohaather was an emphatic winner that day, having previously endured a luckless run behind Circus Maximus in the Queen Anne Stakes at the same course on his return last month, when he and jockey Jim Crowley simply had no room to manoeuvre.

Tregoning is seeking his first Group 1 win since landing the Derby with Sir Percy in 2006 and said: “It’s a tough order but I don’t think we could have Mohaather any better and he deserves a crack at it. He took his race in the Summer Mile very well and was back cantering the next day.

“He went through the gears well last time and Dane [O’Neill, his jockey] gave him just the one tap. If he’d given two or three, then he would have probably won by six lengths. It was a good exercise as it proved he got the mile well and it gave us an indication that we are good enough to have a go.

“I don’t see why he won’t handle the track because he’s a neat horse who travels well and has plenty of speed. Hopefully he’s going to run a big race.”

The Queen Anne was run at a steady pace and it could be the same story on Wednesday as there are no habitual front-runners in the field. However, Tregoning says the potential lack of an end-to-end gallop does not concern him.

He said: “This horse has an electric turn of speed, so I’m not worried about it. If they go no pace, they go no pace. He has got enough speed to win over six furlongs, as I’ve always said.

“It didn’t work out for us at Royal Ascot but that’s racing, it can happen, and we just draw a line under that and move on. It’s in his past and there’s no point dwelling on it. The horse has done nothing wrong this year and we are there to win if we are good enough.”

Circus Maximus prevailed in the Queen Anne Stakes, staying on gamely to win by a head from Terebellum. His other victories at the highest level, all achieved with Ryan Moore in the saddle, have also been by small margins.

Aidan O’Brien, his trainer, seeking a fifth Qatar Sussex Stakes victory, said: “Ryan [Moore] will tell you that Circus Maximus only just does enough to win. At home he will do the same thing, no matter what you work him with. He will just about put his head in front of a horse, or wait for a horse. We don’t know what his limit is.

O'Brien will also be represented by Wichita and Vatican City. Wichita followed up his near-miss in the QIPCO 2000 Guineas by finishing third in the St James’s Palace Stakes at Royal Ascot, while Vatican City seemed betrayed by a lack of stamina on his latest start when failing to make an impact in the Investec Derby,

Siskin won each of his four races as a two-year-old, including the Group 1 Keeneland Phoenix Stakes at the Curragh. He had to be withdrawn from his intended final start last term, when becoming unruly in the stalls before the Juddmonte Middle Park Stakes at Newmarket, but showed that experience had left no lasting scar when landing the Irish Guineas on his return, in the process giving the trainer/jockey combination of Ger Lyons and Colin Keane their first Classic victory.

The last horse to still be unbeaten after winning the Sussex Stakes was the mighty Frankel, the only two-time winner of the race. Siskin, like Frankel, is owned by Prince Khalid Abdullah, who has scooped a record-equalling seven Sussex victories.