Wasps duo James Haskell and Riki Flutey are reported to have virtually trebled their wages by signing for Parisien glamour club Stade Francais and Brive, respectively.

Racing Club Metro in Paris are said to be keen to sign Jonny Wilkinson and there are fears this could be just the tip of the iceberg as English clubs struggle to match money on offer across the Channel.

French clubs are not bound by a salary cap and the current exchange rate has made a move to the Top 14 increasingly attractive.

But Twickenham’s elite rugby boss Rob Andrew this week warned the France-bound will be placing their England careers at risk.

And Thomas believes moving outside the Premiership could end up costing players big-money sponsorship contracts on the basis out of sight is out of mind.

Danny Cipriani, who is understood to have agreed a new one-year contract with Wasps, is a classic example. His off-field endorsement deals with the likes of Armani and Adidas dwarf his Wasps salary.

Wilkinson has become a millionaire thanks to his commercial interests, not his Newcastle salary - and the same applies across other sports. Think David Beckham, Kevin Pietersen or Tiger Woods.

Thomas explained: “I understand players have got to look after their own fortunes. In the long run there is an argument you could probably be better off staying in England.

“You may not get the same salary but the opportunities that some players have for very considerable endorsement and sponsorship deals far outweighs their salaries.

“I think players should just think about that, and hopefully they do so.”