England's top clubs have voted not to compete next season if the French clubs carry out their threat to boycott.

And Ospreys director Roger Blyth said: "Every club in the participating countries have benefited massively from being part of this tournament.

"It's the flagship of European rugby and to put it in jeopardy is selfish."

Premier Rugby, the governing body responsible for the 12 English Premiership clubs, is in dispute with the Rugby Football Union over shares and voting rights in European Rugby Cup Ltd.

The French and Italian unions have already agreed to transfer ERC shares to their clubs, and the English clubs are asking for equal shares and votes with the RFU in a new five-year commitment to European competitions.

I'm still hopeful that given the magnitude of the competition, sense will prevail and the competition will go ahead Ospreys managing director Roger Blyth

But the lack of agreement in England has prompted the French - who are also concerned over fixture congestion after the World Cup - to threaten to boycott next year's competition.

French clubs will decide on Thursday whether to go through with their boycott, and Blythe says a French and English pull-out would signal the end of next year's competition.

"It would be a bit of a meaningless competition without them," said Blythe.

"But if they do pull out, it would be catastrophic for Welsh rugby. We rely on all the competitions we compete in.

"We're a small nation that needs to better ourselves all the time.

"To be serious about playing at the highest level in world rugby, we need to be playing competitions like the Heineken Cup where we can pit ourselves against the best.

"And also of course, it brings in much-needed funds."

The crisis intensified on Tuesday with the RFU saying they could take legal action if the English clubs, who are contracted to play in European competitions until 2009, carry out their boycott threat.

Blythe says a bitter legal dispute is the last thing northern hemisphere rugby needs, but he is hopeful that both French and English clubs will see there is too much to lose by withdrawing from the Heineken Cup.

"When it was mooted a couple of months ago that the French were going to pull out, everyone thought it was sabre rattling and the prize of the Heineken Cup would be too great a one to jeopardise," he said.

"But it's got to this late stage and rugby does have a great ability to shoot itself in the foot

"If it was not to take place next year everyone would lose out - it would take a long time to regain it's credibility with sponsors etc.

"But I'm still hopeful that given the magnitude of the competition, sense will prevail and the competition will go ahead."