Newcastle Falcons' promotion back to the Premiership has been confirmed.
The Rugby Football Union said on Thursday the Championship table would be decided by a "best playing record formula", with Falcons having won all 15 of their league games in 2019-20.
Yorkshire's relegation has also been confirmed after the season ended early because of the coronavirus pandemic.
Meanwhile, the women's Premier 15s season has been declared null and void after 12 of the 18 rounds were played.
Defending champions Saracens Women led the table by two points from Harlequins in what was the final season before four of the league's 10 teams will have to re-apply for membership.
"We believe that the decisions made provide fair and balanced outcomes for the game and maintain the integrity of the competitions," said RFU president Peter Wheeler.
Newcastle will replace Saracens in the Premiership, after their relegation was confirmed earlier this year following persistent salary cap breaches.
It has not yet been decided how or when the Premiership season will be concluded.
An RFU spokesperson said the professional game board had "agreed to take last year's audit as evidence" that Newcastle would pass the minimum standards criteria required to play in top flight.
But the Championship's second-placed side Ealing, who were 18 points behind the Falcons with a game in hand, having played 14 of the scheduled 22 league games, have said they would take legal advice should they be denied the chance to win promotion.
Newcastle director of rugby Dean Richards described any potential legal action as "distasteful".
'No real sense of celebration'
Falcons were relegated to the Championship last season, the first time they had dropped out of the top tier since 2011-12.
Chairman Semore Kurdi said it had been a "huge collective effort" to win promotion, but also acknowledged "the bigger picture with regards to the ongoing pandemic".
"There is no real sense of celebration at the confirmation of our promotion," he said. "Our thoughts just go out to everyone who has been affected by the whole situation.
"We are doing our best to manage our way through this situation with everyone's best interests at heart."
Wheeler added: "This has been a difficult decision to make in the most unprecedented of circumstances.
"There is no single solution that will suit every club, but the approach taken is one that we believe best reflects the nature of league rugby in England.
"With 80% of the season complete for the community game, we believe our approach is fair and the right one for our leagues. We have clubs that are clear league leaders and worthy of promotion, but also other clubs who have said they would benefit from relegation, to play more meaningful rugby."
Premier 15s decision 'categorically the right one'
Harlequins Women have reached the last two Premier 15s finals but lost out to Saracens on both occasions and will now not get the chance to claim a first league title this year.
Coach Karen Findlay, who is currently working for the Metropolitan Police on the frontline in the fight against coronavirus, says the decision to make the season null and void is "categorically the right one".
"It's odd for everybody," she added. "It's difficult for people but the way I look at it is that it's decisions that are about societal responsibility.
"We have never encountered anything of this nature. Knowing what the NHS is going through it is categorically the right decision to try to do as much as we can to try to battle this virus."