England rugby team at the 2023 Rugby World Cup in Paris. Photo: ©INPHO/Dan Sheridan
The RPA has represented England's players for 20 years in negotiations over fees and commercial deals with the Rugby Football Union (RFU).
The RPA will continue to represent England men until this summer.
The move follows plans by the RFU to introduce 25 hybrid contracts as part of the new Professional Game Partnership (PGP).
The hybrid or "enhanced "contracts would give the RFU closer control over player workload.
On announcing the forthcoming split, the RPA said it would continue to support rugby players away from the England men's side.
The statement added: "A current Elite Player Squad men's representative has placed on record that the squad give the RPA their full backing in supporting players across the English game."
The union will continue to represent England's women, although some of the Red Roses players are also represented by the Women's Rugby Association (WRA).
The RPA represents more than 800 active male and female players, along with more than 400 former players, but the departure of England's men will represent a loss in income.
In 2020, England prop Ellis Genge announced plans to start a new union to gain better "support and legal advice" for elite players
While his new union never emerged it was one of the first signals that not all the players were happy with the RPA relationship.
No information on the new agency understood to represent the England men has yet been released.
This story first appeared on the BBC