Great Britain have not lived up to expectations in the Tri-Nations

Great Britain have struggled in this year's Tri-Nations and Millward thinks the number of "imports" has limited coach Brian Noble's selection options.

"GB can't generate half-backs who are good enough to compete at Test level," Millward told BBC Radio Five Live.

"There should be a maximum of three overseas players at each club. That way you can bring youngsters through."

Millward said the over-reliance on foreign imports was stopping young British players' development.

"I know of one team who will have a minimum of 10 overseas players next season and that's not good," said the Australian coach.

"I think last season there were only five clubs with British half-backs.

"At junior level and club level, the British game is very strong but at international level the pool of talent isn't big enough to pick players from."

Former Wigan scrum-half Luke Robinson is one example of a young British player who found his first-team opportunities blocked by overseas players.

The 20/20 rule inhibits the progress of youngsters in this sport Wigan coach Ian Millward

Robinson, who played for England against New Zealand on Sunday, left Wigan for Salford following the arrival of Australian Dennis Moran in 2004.

"I've worked out that there's well over 120 imports in the British game next year," said Millward.

"So how do you solve it? There's human rights issues involved, so you can't just say to a bloke, 'You're an import, clear off'.

"What needs to happen is for all the chairman to get in a room and reach a gentlemen's agreement and - over a three-year period - to have just three imports."

Millward also believes British rugby league officials need to look at the impact of the 20/20 rule, which stops clubs having more than 20 players earning over �20,000 a year.

But he does not have a problem with Super League's salary cap of �1.8m per club on players' wages.

"Ultimately the 20/20 rule inhibits the progress of youngsters in this sport," he said.