The England Rugby Union plans to only select players for the England team who play for domestic clubs following the 2011 World Cup.
Three members of the England squad - Jonny Wilkinson, Tom Palmer and James Haskell - currently play overseas.
French clubs are currently the wealthiest in global rugby, and a host of world stars have moved there in recent times, including New Zealand prop Carl Hayman - another of Toulon's acquisitions - and Racing Metro's South African star Frans Steyn.
Among England players believed to be eyeing a move to France after the World Cup is Sale's loosehead prop Andrew Sheridan, who has been linked with Toulon.