Promotion and relegation from the top-flight Prem is to be scrapped from next season as part of a major shake-up of English club rugby union.
A "criteria-based expansion and demotion model" will take its place instead following an "overwhelming" vote on Friday in favour of a new-set up by the council of England's governing Rugby Football Union.
The Prem, as the English Premiership is now known, will look to expand from 10 teams to 12 teams by 2030, with a further increase possible if clubs meet criteria on and off the field.
As a result, teams such as Wasps, Worcester and London Irish – all of whom went bust in the 2022/23 season – could now return to the top flight.
"We recognise that moving away from a traditional system of automatic promotion and relegation represents a significant change," said RFU chief executive Bill Sweeney following Friday's vote.
"However, it is equally clear that the professional game must evolve if it is to thrive.
"The previous structure was not delivering the financial stability, investment confidence or wider system benefits the game now requires."
At present, promotion and relegation to and from the Prem is theoretically possible via a play-off is with the top-placed side in the Champ.
'LANDMARK AGREEMENT'
But London club Ealing Trailfinders, consistently the best team in the second tier, have failed to meet the existing standards, especially around stadium size, meaning promotion and relegation has been effectively suspended for several seasons already.
A team has not been relegated from the Prem since Saracens in 2020 after they suffered a points deduction for breaching salary-cap regulations.
The London club later become the last team to earn promotion to the Prem after returning in 2021.
The financial strain of trying to get into the Prem – and the potentially huge costs of relegation – have long been cited as a reasons for ditching the current set-up.
A joint statement issued Friday by the RFU, Prem Rugby, second-tier Champ Rugby, Premiership Women's Rugby and the Rugby Players' Association, said "a landmark agreement" was "overwhelmingly approved by an RFU council vote today".
"It is being introduced in recognition that the previous system was not delivering financial sustainability, discouraging long-term investment and failing to generate meaningful benefits for the wider rugby ecosystem," the statement added.
An expansion review group will be established to assess which clubs are ready to join an increased Prem before relevant teams go through a formal tender process.
Prem chief executive Simon Massie-Taylor said: "We are now firmly on the path to a more prosperous and brighter future for Prem Rugby.
"Our vision is to become the best league in the world –- for fans, players and investors in current and future Gallagher Prem clubs – and these important changes throughout the game will help us achieve this."
Clubs included in the top flight will have to operate a team in Premiership Women's Rugby or fund a meaningful regional women's development plan if they are to avoid fines for non-compliance.