London Irish have become the latest Premiership club to announce their intention to start a women's team to play in the Premier 15s.
They intend to apply for a franchise in the next intake of teams in 2023.
England's 2014 World Cup-winning assistant coach Graham Smith has been named women's head of performance.
He said: "The club has a shared passion, purpose and vision to take women's rugby at London Irish to the next level."
Every three years the Rugby Football Union opens a bidding process for clubs to have a team in the league, meaning there is no promotion or relegation.
In 2020 Exeter Chiefs Women and Sale Women joined the league at the expense of Richmond and Firwood Waterloo Ladies.
London Irish plan to share coaches and talent with St Mary's University Twickenham and work with them as an education partner.
Mary Fyfe, the Exiles' director of women's rugby, said the move was "a new chapter in our history" and that the growth of their women's set-up was "a natural progression for the club."
The league currently operates with 10 teams but earlier this year RFU chief executive Bill Sweeney told the BBC the league could grow to include different conferences.
However, he thought a second division for the league was a "way off".