"The decision by Ireland and Scotland smacks of childishness and I can't understand it.
"We told them that we had signed up to the Anglo-Welsh Cup, but also that the Celtic League was our most important competition and that we remain totally committed to it.
"Whether Italy came in and we played the league home or away, or they stayed out and it remained home and away, we felt we could accommodate the cup tournament.
"You have to feel sorry for Irish and Scottish rugby supporters.
"Given the state of their rugby on and off the field, I'd have thought Scotland would do everything in their power to play in a meaningful tournament.
"This seems a final decision from them over the Anglo-Welsh issue, but I'm always hopeful and we'll see what happens in the next few days."
The Anglo-Welsh Cup will consist of the four Welsh regions and 12 Zurich Premiership sides competing in a group stage with four teams per group.
The knock-out stage will begin in March with the final at Twickenham the following month.
There remains optimism on all sides that the Celtic League can be revived for the season after next, with the possible inclusion of Italian clubs, who had been mooted as replacements for the Welsh this season.
A statement from the Celtic League Association said: "The Scottish and Irish rugby unions are disappointed that the Welsh Rugby Union did not consult its partners in the Celtic League prior to making commitments to the Anglo-Welsh Cup, given the serious negative consequences it has on the Celtic League.
"It is hoped that discussions may continue between the Irish, Scottish and Welsh rugby unions along with the Italian Rugby Federation to structure a new competition in season 2006-07 which would incorporate four Irish teams, three Scottish teams, four Italian teams and four Welsh teams."
The Scottish hierarchy are far from happy with the actions of the WRU.
An SRU spokesman said: "This is clearly far from perfect. There is a dilution in the breadth of the competition for this coming season.
"But we sincerely hope Italy and Wales will join us in a newly-expanded competition in 2006-07.
"We have to try to maximise revenue and this is clearly not clever from that viewpoint.
"But, from the view of the elite player, there will be 12 guaranteed games in the new Scottish-Irish competition.
"There will also be an unspecified number of games in a cup tournament and Glasgow and Edinburgh will play in the Heineken Cup.
"We will also have eight international matches which would take us to 26 before the cup competition is taken into account.
"Experts talk about 30 to 33 games being the optimum number of games for a player to play in the season.
"In some respects, we are not all that far away, but we are not going to pretend it is a situation we are happy with because we are not.
"There may be some who might seek to paint this as an unmitigated catastrophe but I don't believe it is that either.
"However, in terms of player burn-out, we are not that far away from the optimum number of games.
"But the route we have arrived at for that number of games is clearly not clever."
The story can be read in full on Rugby News.