David Moffett has given the merger plan his seal of approval

Chief executive David Moffett said the WRU will take an advisory role in talks between the Blues and Celtic Warriors.

Moffett said: "We are not going to be playing an active part in bringing this merger about, but neither are we going to stop it."

He added: "We will not push any two regions into a merger or otherwise. It will be a mater for them."

The proposed merger appears to have been prompted by financial problems at Cardiff.

Moffett, who has always preferred the option of four instead of five regions, said he was not surprised that the "financial reality of Welsh rugby was beginning to bite".

He added: "We still believe that four regions is the right number from a player strength and financial position, but we've got five.

"We will remain with five unless two of the regions wish to form a bigger region as is the case here."

Moffett acknowledged the plan was very much in its infancy and would probably meet with opposition from fans, the regions' shareholders, broadcasters and European club rugby bosses.