The boss of National Lottery operator Allwyn UK is stepping down after a nearly three-year tenure leading a “long-overdue transformation”, the company has announced.

Andria Vidler will leave her role as chief executive next month following an agreement with UK chairman Justin King.

She will be replaced by Phil Walker on an interim basis from September 7, who joins from betting shop chain William Hill.

Ms Vidler said she decided it was the “right moment” to hand over to a new boss to drive growth following the completion of a major tech upgrade to the lottery.

She took the helm at Allywn’s UK business in October 2023, before the company took over from Camelot to run the lottery in early 2024.

The start of her tenure was chequered by legal issues which delayed plans for new draw-based games and held back the amount of money the National Lottery can give to good causes in the early part of Allwyn’s 10-year licence.

This followed delays to a planned switchover to a new technology provider.

This year, Allywn completed the lengthy £450 million major tech upgrade to the lottery, which involved moving 18 million player records and more than three billion historical transactions from old platforms to new ones, updating the lottery website and mobile apps, as well as transforming the technology used by retail partners.

It also paved the way for the group to unveil the biggest overhaul to its draw-based Lotto game since its launch in 1994 and the first new draw-based game in the National Lottery’s history this summer, with the launch of the UK-specific version of the world’s biggest jackpot game, Powerball.

The company said Mr Walker’s appointment will help drive forward a new phase of growth for the business while it searches for a permanent successor.

Mr Walker spent six years at William Hill in roles including its chief commercial officer and managing director for the UK and Ireland.

Ms Vidler said: “It has been a huge privilege to lead Allwyn UK through such an important period for the National Lottery.

“The last three years have required enormous focus and commitment from colleagues right across the business, and I am proud of what we have delivered together.

“But transforming the National Lottery is a marathon, not a sprint, and with the major transition now complete, and the National Lottery in a stronger position to keep delivering for the nation, this feels like the right moment for me to pass on the baton.”

Chairman Mr King said: “Since Andria joined us, she has led from the front through an intense period of change, helping to complete the much-needed and long-overdue transformation of the National Lottery.

“With the major transition milestones delivered, now is the right time to look to the future and build on the solid foundations that have been laid to create a strong platform for future growth.

“We are pleased to welcome Phil as interim CEO as we continue to modernise and strengthen the National Lottery for players, retailers and good causes.”