Cornish Pirates will, theoretically at least, have a route into the top flight
The Gallagher Premiership will expand to 14 clubs from the 2022-23 season with a temporary pause placed on relegation.
Saracens are to rejoin the English top flight after being crowned Greene King IPA Championship winners earlier this month, increasing the number of teams for the 2021-22 campaign from 12 to 13.
And the Rugby Football Union’s council have now voted to add another team for the following two seasons, with a play-off between the Premiership’s bottom side and the winners of the Championship deciding relegation in 2023-24.
Unless the council agrees otherwise, from 2024-25 promotion and relegation will revert to an annual one up, one down basis.
"The changes will undoubtedly benefit the game of rugby in England as we recover from the effects of the pandemic," RFU president Jeff Blackett said.
"This is not ring-fencing the Premiership as some have suggested. In three of the four seasons covered by this and our previous decision, a Championship club will have the opportunity to be promoted.
"Council has control of what happens thereafter and is committed to maintaining the integrity of the league structure by ensuring that access to the Premiership will be retained in the future."