Craig Williams is heading to Royal Ascot for the five-day carnival hoping to be aboard two leading Australian contenders.

Williams will find out late on Wednesday whether he has the ride on the David Hayes-trained Criterion in the Prince Of Wales's Stakes, while the star jockey has been booked to ride Brazen Beau if the colt runs in the Diamond Jubilee Stakes.

Joao Moreira has ridden Brazen Beau to his two Group One wins in Australia and had first refusal but the Hong Kong-based hoop is unavailable for the Diamond Jubilee on the final day.

Moreira will ride Brazen Beau if trainer Chris Waller elects to run the colt in the King's Stand Stakes on Tuesday.

Waller is favouring the Diamond Jubilee but a decision is expected later this week after the trainer sees Brazen Beau in England and monitors the weather.

"I'm delighted to pick up the ride on (Brazen Beau)," Williams said.

"The owners and Chris Waller always told me exactly where I sat in regards to the jockey situation, they were always honest and true to their word.

"I was more than delighted to be able to be part of his preparation and most importantly it looks like now I hope to be part of his main goal.

"He's had an amazing preparation for the race."

Hayes will meet with Criterion's owner Sir Owen Glenn to finalise a jockey with chad Schofield and Damien Oliver also in the mix.

Williams rode the horse to win the $4 million Queen Elizabeth Stakes during the Sydney autumn carnival.

"I've spoken to David. He's really happy with Criterion and I'm hoping to be still on Criterion," Williams said.

Williams will arrive in England on Sunday and will be at Royal Ascot for the week.

He will touch base with other trainers he has previously ridden for in Europe and Australia to see if he can pick up other rides during the carnival.

Williams rode Brazen Beau to second in the Lightning Stakes.

He has ridden the colt in jump-outs including his final hit-out at Flemington before the sprinter left for England and is convinced he's on target for Royal Ascot.

"I was pretty happy to report after the jump-out that if he gets off the aeroplane and has the same form and is feeling the same way as when he left, he's going to take a lot of beating," Williams said.

Brazen Beau arrived in England last Friday morning along with fellow Royal Ascot contenders Shamal Wind and Wandjina.

The colt is at his best on firm ground, and if it looks as if it will be wet late in the week, Waller will recommend he run in the King's Stand Stakes on Tuesday (Wednesday AEST).