England's top clubs are to hold formal discussions to consider the extraordinary request by Toulon - the home of Australians Quade Cooper, Matt Giteau and Drew Mitchell - to quit the Top 14 and join the Aviva Premiership.
Premiership Rugby, the tournament organisers, refused to dismiss the notion out of hand after confirming on Thursday they had received a letter from Toulon president Mourad Boudjellal on Wednesday.
"We will give it due consideration and respond," said a Premiership Rugby spokesman.
Boudjellal insisted his approach was "serious", telling L'Equipe that his club's Premiership presence would offer "a huge added value".
"This is not just a provocation," insisted Boudjellal, whose side are in pursuit of a fourth successive European title but have been at odds with the Ligue National de Rugby and the French Rugby Federation over tightening salary cap regulations and the number of overseas players in club squads.
"The economic future is better in England than France, given how the leagues are run. The English make good decisions. For them, besides [being] a big first, it would be a huge added value. I'm serious. Monaco compete in the French Ligue 1 and no one finds that incongruous."
The audacious bid by Toulon, the reigning European champions, appears to have little hope of success but could be one of the first public declarations about the aspiration held by some at the top end of the club game for the creation of a European super league in the medium term.
Premiership clubs also discussed last year increasing the league from 12 to 14 clubs and ending promotion and relegation, which is likely to have given hope to the Toulon president that a new club would be welcome. But even if the 12 Premiership clubs agreed to Toulon's request, the matter would then have to be considered by both the Rugby Football Union and the FFR.
While there is nothing in the RFU rules that state that new clubs must be based in England, they must work their way up from the bottom of the league structure, which would kill Toulon's interest unless the governing body's council agreed to their entry.
Boudjellal indicated that he was also considering buying control of an English club.
The London Telegraph