In a statement from the IRFU, the Unions have also sent a clear warning to the English clubs' plans for a breakaway competition - warning that cross-border club competitions "must not conflict" with the development of the sport by the Unions.

Premiership Rugby, the umbrella organisation for the leading English clubs, has consistently said it no longer recognises ERC and will not participate in competitions under its jurisdiction.

In their statement, the five unions - minus the Rugby Football Union - said they had agreed the following.

“A European club competition is to take place during the 2014/2015 season following an optimised sporting and economic format with 20 teams, no matter how many countries are involved.

“The competition will be driven by the existing organisation (currently named ERC) which will remain in charge of the centralised sale and management of all commercial rights, amongst other things.

“Discussions over governance will be pursued in order to optimise the internal functioning of the existing organisation (currently named ERC).

“The common aim is to move eventually towards the integration of European competitions within an all-encompassing European rugby framework.”

The comments are unlikely to set alarm bells ringing at Premiership Rugby, though.

They announced plans for a Rugby Champions Cup in September, a joint enterprise by the Premiership clubs and France’s Top 14 under the Ligue Nationale du Rugby banner.

The four Welsh regions – Cardiff Blues, Ospreys, Newport Gwent Dragons and Scarlets – subsequently announced that they wanted to join the Anglo-French model.

There is no indication in the unions’ statement tonight which clubs would participate in a union-run European competition.