Derek McGrath has insisted that "the door is still open" regarding negotiations over the future of European rugby's prestige club competition the Heineken Cup.
Premiership Rugby and Ligue Nationale de Rugby are forging ahead with their own blueprint - the Rugby Champions Cup - next term, and have also extended an invitation to Celtic and Italian teams to join them.
Top English and French clubs are currently serving a notice period to leave European Rugby Cup-run competitions, and they will not attend summit ERC talks planned for 23/24 October.
Celtic unions Wales, Scotland and Ireland released virtually identical statements last week saying they would not sanction their teams to play in any future tournaments not approved by the International Rugby Board.
And ERC chief executive McGrath is adamant that he believes a solution can be found, despite the odds being overwhelmingly stacked against that happening.
"ERC supports and wishes to encourage everybody back to the table. There is a lot of activity going on to try to find solutions," McGrath said at Monday's English and French launch of this season's Heineken and Amlin Challenge Cup competitions in Cardiff.
"We have stated many times that we absolutely believe that we will only find agreement when we have the full engagement of all the parties around the table. We haven't had that yet.
"We haven't had engagement and we haven't had negotiation, which is critical to find progress. The door is still open to find solutions.
"There is still time, but all parties bear a responsibility to find those solutions, and walking away is not respecting the obligations to those, in particular, who are not sitting at the table - the fans, the players, the sponsors - who have a significant interest in the future of the competitions.
"We would like to get solutions as soon as possible. The meeting we have called for October 23 and 24 is not that far away if we can get proper engagement. We would encourage everyone to get back to the table because solutions can be found.
"We absolutely believe the future is best served by doing what we have all been doing for 18 years. I sincerely believe it is in everyone's best interests to come to the meeting."
"We absolutely believe the future is best served by doing what we have all been doing for 18 years" - Derek McGrath
Speaking to Press Association Sport last week, Premiership Rugby chief executive Mark McCafferty was in a defiant mood.
"We are certainly not attending the meetings on October 23 and 24 that we have been invited to, and the French clubs aren't either," he said.
"As far as we are concerned we are not in ERC competitions, and neither are the French clubs.
"From our perspective, those competitions in their current form are over. We don't have any dispute with ERC, from our point of view, which is why the appointment of a mediator (Canadian lawyer Graeme Mew) by ERC is a bit odd.
"We've served notice, we are discharging all of our obligations during that notice period, and at the end of that notice period we will go to play in new competitions. There is no dispute about that from our point of view.
"We are putting a competition format and a financial structure in place through the Rugby Champions Cup that is going to be attractive to everyone."