Bill Sweeney denies the Rugby Football Union has “sold out” after insurance giants Allianz bought the naming rights to Twickenham for over £100million.

From September 1 the 82,000-capacity home of English rugby will be known as ‘Allianz Stadium’ in its first rebrand since it opened in 1909 with the deal injecting cash into the elite and grassroots levels of the game.

RFU chief executive Sweeney has revealed that the decade-long partnership will provide in excess of £10million a year at a time when the sport is facing significant financial challenges.

The response to the agreement has been mixed with many supporters voicing their discontent at the name change online, particularly at the exclusion of Twickenham from the new title.

Other treasured national sporting arenas such as Wembley, Lord’s and Wimbledon still retain their historical names, but Sweeney insists this is the right direction for the RFU to take.

“I really don’t believe we’ve sold out. It’s an iconic stadium, it’s the home of rugby. Experiences here are incredible, people love coming here,” Sweeney told the BBC.

“But we believe this will help us build on the legacy of the stadium and will take us into the future decades from here.

“The investment from Allianz will enable us to make Twickenham an even better experience for fans and players.

“We believe this is an investment into the future with the sort of partner we need to go on that journey. It’s money that we need to invest back into the game.

“It’s a multi-year commitment and it’s well over £100m, so it’s a fair value for what you’d expect for stadium naming rights these days.”

Twickenham is now the eighth sporting venue around the world to carry the Allianz branding and the RFU is the last of the four home unions to sell the naming rights to its home ground, in the process negotiating a more lucrative deal than its rivals.

The PA news agency understands that retaining Twickenham in the title was not an option if an agreement with Allianz was to be reached, with an RFU insider stating “it’s a really good deal for rugby”.

“The new name aligns with our approach to other stadium partnerships across the globe and over time it will mean the Allianz Stadium name is adopted more fully,” an Allianz spokesperson said.

“We recognise that Twickenham has an extraordinary heritage and we look forward to helping develop this iconic venue for the future.”

The partnership has received the approval of Newcastle director of rugby Steve Diamond, who recently worked for the RFU in a consultancy capacity.

“Selling the naming rights of Twickenham is magnificent for rugby, which has been through its worst period. But we are not out of the water yet,” Diamond said.

The RFU in February revealed plans to begin a £300million upgrade of Twickenham in 2027 after rejecting a proposal to make Wembley the new home of English rugby.

Buying a 50 per cent share in Wembley from the Football Association was considered by the RFU’s board in March last year before the idea was discounted without a formal approach to the FA being made.

The first fixture to be played at Twickenham under its new name is the Red Roses’ clash with New Zealand on September 14.