England today hardened their position on selecting overseas-based players by declaring they will only be chosen after the 2011 World Cup in "exceptional circumstances".
The Rugby Football Union's chief executive John Steele has written to all England internationals and their agents warning of the repercussions should they play their trade outside the Aviva Premiership.
Steele believes the RFU's wish to only pick from the English league will improve the team's chances of winning the 2015 World Cup on home soil.
In the letter, seen by Press Association Sport, Steele writes: "As things stand today we have a number of elite players in various squads and clubs outside England, principally in France, and you may be considering that as your next career move.
"If that is the case then I wanted to let you know that it is our view that we are best served by having our England Elite Player Squad (EPS) and our England Qualified Players (EQPs) all playing in England at English clubs.
"So I would like to confirm that it is our strong intent, from the end of Rugby World Cup 2011 through the RWC 2015 cycle, to select our Elite Player Squads at all levels entirely from players playing at English clubs where at all possible.
"I would stress that this is not a change to our selection policy itself, players remain entirely free to play outside England should they so wish, but you need to understand that it is our absolute intention that we only select from overseas clubs in exceptional circumstances.
"It is for you and your agent to decide if you are willing to take that risk.
"I would further reiterate the crucial point that it is our firm intent to only select players playing at English clubs."
EU employment law has forced Steele to pick his words carefully, but it remains a clear statement of intent from the RFU.
It is hoped the stance will halt the player drain to the French Top 14 where clubs bankrolled by wealthy benefactors are able to offer large contracts.
Only yesterday Sale admitted they face a battle to keep their Lions prop Andrew Sheridan, who is considering the option of joining Toulon next summer.
At 31-years-old Sheridan is unlikely to be required for the 2015 World Cup, but he will still be in action well beyond next year's tournament.
England currently have three members of their senior elite squad - Jonny Wilkinson, James Haskell and Tom Palmer - playing club rugby in the Top 14.
Palmer has one more year left on his current contract with Stade Francais and it is understood he would not be penalised for that - unless he signed an extension.
But Haskell's agreement with Stade and Wilkinson's deal at Toulon both expire at the end of the current season, ensuring they must then return home if they are to avoid harming their England careers.
Haskell has previously been in conflict with Stade over his release and Rob Andrew, the RFU's director of elite rugby, stressed the importance of retaining control of the players.
"We've had some difficulties over contracts with the French clubs," said Andrew.
"It's also more difficult to manage the players under the terms of the EPS agreement when they are in France.
"We think it's in the best interests of the player for his long-term international career and the England team if we go down this road.
"We've got an eye on the future beyond 2011. We want the young England players who we are developing and who we believe will be very good internationals to stay in England.
"That way we can look after them from an international point of view.
"This is putting a marker down for guys who are thinking of going now or extending contracts.
"It's a new development (the exodus to France) and we've tried to manage it as best we can over the last 18 months.
"But now we're trying to give some notice and restrict any problems we might have in terms of preparation of the England team in the build up to 2015."
England manager Martin Johnson, whose current contract expires after next year's World Cup, agrees the move will benefit the national side.
"It's virtually where it is now, but it's harder. We said to some of the guys when they went away that it will be harder," said Johnson.
"It's tougher when players are over there in terms of getting their release and the fixtures in France don't marry with internationals like here.
"The number of games they play in France will have a cumulative effect on players over the years as well."
Andrew revealed there is currently no move to review Johnson's contract with talks over his future on hold until after next year's World Cup.