Premiership Rugby is adamant that its new Rugby Champions Cup will go ahead next season, with or without the RaboDirect Pro12 teams, and its chairman, Quentin Smith, said claims that English clubs are looking to grow rich at the expense of rugby in the three Celtic unions and Italy are "ill-informed and offensive".

Smith confirmed that Premiership Rugby would not be meeting Graeme Mew, the mediator hired by European Rugby Cup to help its stakeholders find common ground over a new accord, and it will not attend the Dublin summit on 23 October which has been called by ERC.

Smith is himself a mediator and said the idea that Mew would be able to make a difference was a non-starter. "There is nothing to mediate over because Premiership clubs are not in dispute with ERC and we will not be involved with it after this season having served valid notice.

"We will be announcing details of the Rugby Champions Cup next month and all our energy is going into creating that infrastructure.

"Ever since we gave our notice last year, along with the Top 14 clubs, to withdraw from ERC, we have been very careful about what we say publicly because we do not have an argument with anyone.

"We simply want to set up and run a different tournament. So to hear comments in recent weeks about our motives from certain administrators, including claims that the English club owners want more money just to line their own pockets, is bitterly disappointing.

"The remarks are both ill-informed and offensive. The extra income raised by the Rugby Champions Cup will be put straight back into the game. Our owners are all fully committed to the English game and getting their businesses into profit.

"We are happy to speak to Roger Lewis [the Welsh Rugby Union chief executive who said last week he was prepared to meet the clubs to help find a way of ensuring there was a six-nation club tournament next season] or to anyone else, but we will not be deflected from setting up the Rugby Champions Cup.

"We want the other countries to join us and there is no reason why they should not as everyone will be better off."

Smith's comments come on the eve of what could be the last Heineken Cup, a tournament that was established in 1995. "It has been going for a long time and it has been a very popular tournament," he said. "Our aim is to establish an even more successful and outstanding European competition and we want the unions to work with us.

"I cannot see any reason for a union to block this initiative. It would be in no one's interests if this ended up in court. That is very much a last resort as far as we are concerned.

"I have heard it said that we are doing this so that the tele vision contract ERC agreed with Sky last year falls, but the English and French clubs gave their notice before that deal was negotiated. It had nothing to do with us and we have never been bound by it. We have an agreement with BT [Sport] and we intend to deliver on it."

The Wales and Lions captain Sam Warburton's desire to sign a new contract with Cardiff Blues has been held up by the uncertainty over Europe. He has told the region he wants to stay but if there is no Heineken Cup and the WRU puts a block on its four professional sides playing in the Rugby Champions Cup, his employers face a 25% drop in income.

"I find it hard to believe there will not be a European competition next season that does not incorporate every country because it would not be very prestigious," he said. "You trust something will be sorted out and I am quite relaxed about it all. European rugby is not the be-all-and-end-all in my contract talks.

"I get looked after by the Blues and we have an exciting team which can be real contenders in a couple of years if we keep players. It makes sense for some players to move but my preferred option is to stay and I am hoping something will be sorted out this side of Christmas.

"The concern is that it ends up dragged out for so long that you end up with nothing on the table. There will have to be a stage where there is a deadline because you cannot wait until the final day of the season. It is a weird situation to be in."

Warburton said he did not think a Rugby Champions Cup made up of teams from France and England would be a draw for players. "It would be hard to say you were European champions. If the Rabo sides were not in it, we would have a hugely competitive, attractive league and more rest time so your body would benefit."