Oliver Brown odds-on to win at Royal Ascot

The retailer has enjoyed a 50% jump in revenues across its range

Camilla, Duchess of Cornwall and Prince Charles, Prince of Wales as they are seen viewing horses in the parade ring from the Royal Box on the second day of Royal Ascot in London, 2013

Menswear specialist Oliver Brown — the only firm able to sell top hats inside the gates of Royal Ascot — has seen a spike in sales ahead of the annual racing event.

The retailer has enjoyed a 50 per cent jump in revenues across its range, with sales exceeding £300,000. Oliver Brown expects this year’s Royal Ascot, which kicks off tomorrow, to be a record.

Owner Kristian Robson said: “The top hat business is integral to our brand’s success. Production of silk top hats ceased in the early Seventies, and prices of vintage hats have risen sharply as a result.

"Coupled with the fact that very few vintage hats fit modern day heads, original hats are increasingly rare and desirable.”

The business is the oldest independent top hat retailer in London and last week sold an antique silk version for £12,000. Among the items for sale at Ascot by Oliver Brown will be a gold silk top hat which has a price tag of £25,000.

Celebrity customers to Oliver Brown in the past week included Rory Bremner and footballer Michael Owen.