Premiership Rugby's major shareholders are set to meet this week following latest developments in a crisis that has gripped the European club game.
Mark McCafferty, Premiership Rugby's chief executive, has suggested that English teams will not play in European competition next season.
It follows Ligue Nationale de Rugby's announcement last Thursday that French clubs would be pulling out of a proposed Rugby Champions Cup formulated by Premiership Rugby and LNR and supporting a 20-team event backed by Irish, Scottish, Welsh, French and Italian unions under the auspices of European Rugby Cup instead.
How many French clubs actually end up playing in that proposed event, though, remains to be seen.
Premiership Rugby has consistently said its clubs will not participate in ERC-run tournaments, with a two-year notice period to quit ERC being completed next June.
Not playing in Europe next term is now a serious possibility, although Press Association Sport understands detailed discussions on all aspects of the European debate will feature on this week's agenda.
"That's the most likely outcome," McCafferty told the Sunday Telegraph, when asked if English clubs would not play in Europe next season.
"It's the clubs' call on that, but from my perspective I can't see at the moment how it would be feasible for us to be in 2014-15 European competitions, if the unions, as they have said, are going to run a 20-team competition through ERC.
"We knew the French union was putting the French clubs under a lot of pressure.
"Those clubs are on a very tight timetable with regards to the signing of their new agreement with the French union and for their own domestic TV rights deal. But we were not pleased with the way it came out all of a sudden.
"I think the French clubs will say they won't play and the French union will tell six of them they have to play in this 20-team competition."
In the event of English isolation in Europe, an expanded Aviva Premiership might be considered.