Toulon president Mourad Boudjellal has launched an audacious bid to see his three-time European champions join the English Premiership.
A Premiership Rugby spokesman confirmed to Press Association Sport that a letter was received via email from the French club on Wednesday night.
Multi-millionaire comic book publisher Boudjellal's move looks highly unlikely to succeed, although the possibility of England's Premiership clubs discussing it should not be ruled out.
Boudjellal has had an ongoing and often bitter battle with organisers of the Top 14 - France's premier domestic competition - about matters such as the 10 million euros (NZ$16.7 million) salary cap, and most recently, new rules that were introduced last summer regarding player bonus payments now being part of the cap if they amount to more than 10 per cent of a player's salary.
Toulon's expensively-assembled squad is packed with world stars like Bryan Habana, Matt Giteau, Ma'a Nonu, Leigh Halfpenny, Quade Cooper, Juan Martin Fernandez Lobbe and Duane Vermeulen.