Leicester rugby director Richard Cockerill has stressed the need for an equitable qualification process to underpin any future Pan-European competition.
English and French clubs are pressing ahead with plans to launch a new Rugby Champions Cup next season, and they will not attend scheduled summit talks by European Rugby Cup on October 23 and 24 aimed at thrashing out a new Heineken Cup agreement.
ERC chief Derek McGrath says "the door is still open" for Premiership Rugby and France's Ligue Nationale de Rugby to be part of a new tournament agreement, but it appears a forlorn hope, at best.
Premiership Rugby and LNR want Celtic and Italian teams to join their venture, and Cockerill said: "It's very important that all countries are represented, but that has to be on the right terms.
"Premiership teams are battling hard every week to qualify for Europe, and that affects you for the next 12 months.
"Why is it all right for Leicester, Bath or Wasps to miss out on Europe, but it's not all right for Munster or Leinster to miss out?
"If you want to be in the best tournament, you should qualify for it. If you're in the top six of the Rabo (RaboDirect PRO12) you are in it, if you're not you're not. Makes sense to me."
Approval for the breakaway competition is required from the Rugby Football Union, French Rugby Federation and International Rugby Board.
Potentially, either the English clubs or RFU could deny players involvement in Test rugby should a bitter dispute ensue, but Cockerill insists England would suffer most from such an outcome.
"Players are contracted to their clubs, winning the Premiership is ur bread and butter, that's what we do," he added.
"The hypothetical question that if the union doesn't support that and excludes every Premiership player from playing for England, then it will do very well to sell out Twickenham using players from the Championship.
"That's why this has to work. It could go to the 2015 World Cup without any players. That'll work well."
Leading Welsh regional coaches Simon Easterby and Phil Davies, meanwhile, have both stressed the need for an end to the current impasse.
Scarlets boss Easterby said: "The sooner this is resolved the better from our perspective.
"It has gone on long enough. Assuming we can resolve this and the sooner the WRU (Welsh Rugby Union), who are acting on our behalf, resolve the matter with ERC and the other nations the sooner we can concentrate on keeping players and playing in this competition for many years to come."
And Cardiff Blues rugby director Davies added: "We have a few players out of contract at the end of the season, and we plan for the best case scenario, that's all we can do.
"What the reality is after that, who knows? The administrators are quality guys, and hopefully it will be put to bed as soon as possible."