Leading Super League coaches are urging their stars to shun the big dollars on offer in the NRL to stem the flow of English talent to Australia.

Recently, the NRL has been treated to the hugely successful moves of Canterbury’s James Graham, the Burgess brothers at South Sydney, Warrior Sam Tomkins and Gareth Ellis at Wests Tigers, while Wigan’s dynamic winger Joe Burgess will join the Sydney Roosters in 2016.

But St Helens coach Keiron Cunningham and Warrington’s Tony Smith have said enough is enough, arguing the moves are proving detrimental to the development of rugby league in England.

Both coaches agree that playing in the NRL, regarded as the code’s premier competition, has been beneficial to the progress of the players themselves, which has in turn improved the national team, but argue that it is cheapening the domestic competition, which could have a far more lasting impact.

The Super League, with the strong English pound, was for years seen as a threat to the talent on offer in Australia – before an influx of money into the game, mostly through a 2012 broadcast deal worth $1.025 billion over five years, turned the tables.

“We put all these years of work, financing the juniors and training them up, and then they do well and the NRL just pull them out of our game,” Cunningham, who was courted by Australian clubs throughout his decorated career, told AAP.

“It’s good for our international game, but the biggest threat to our game (domestically) is the NRL.

“The competition (for players) isn’t against Wigan or Warrington anymore.

“As soon as you get a good player you know you’ve got to protect them from the NRL as much as you can.

“It’s good to see the English boys doing well over there, but I’d much rather have them in the English comp.”

Smith, whose brother Brian has coached more than 600 games across the NRL and Super League over a 30-year career, said there needed to be a balance.

Smith was able to convince international prop Chris Hill to ignore interest from Australia when he came off contract last year, and says other clubs will be desperate to do the same with their high-profile stars.

“We’ve got to protect too many of our players going but I think the right balance, and the right number, is fine,” he said.

“We’ve got to be careful of too many of our English players heading off at the same time and depleting the depth and talent, and the standard of play.

“We need to make sure were looking after our competition.”