Published Tuesday, 10 September 2013
Rory Best following Ulster's semi-final win last year. (© Pacemaker)
They announced on Tuesday that they intend to leave the competition at the end of the season and replace it with a new one of their own.
Other teams would then be invited to join their proposed competition.
The clubs are unhappy with the structure and revenue distribution within the Heineken Cup.
A statement released by Premiership Rugby has said: "The clubs can only conclude that negotiations on any new European agreement have now ended."
The 2013-14 ERC competitions were due to be the last in their current format amid ongoing discussions, but the clubs of the Pro12 have so far given little indication of backing down.
All parties are to meet in Dublin on Wednesday for discussions over the structure and format of European club rugby tournaments for the 2014/15 season and beyond.
A statement from ERC said: "While there is a shared sense of frustration among ERC's stakeholders at the lack of progress towards a new Accord, the meeting will provide an opportunity for the parties to review the consultation process to date."
© UTV News