Munster, Connacht and Ulster face fixture uncertainty over a round of Guinness Pro12 fixtures after Welsh regions were apparently doubled-booked.
The first round of the Anglo-Welsh LV=Cup has been announced for the weekend of 31 October-2 November, the same weekend as round seven of the Pro12.
As things stands, Welsh regions Ospreys, Newport Gwent Dragons, Scarlets and the Cardiff Blues, are scheduled to play in the two competitions.
Three Irish sides are affected by the potential clash: Ulster are due to entertain the Dragons in Ravenhill; Munster are due to travel to face the Blues, and Connacht are away to Ospreys.
The Pro12 organisers have reportedly said that they will not rearrange their fixtures.
The LV=Cup organisers, the RFU issued the following statement in relation to the clash: “The WRU is currently in negotiations with the regions regarding the Participation Agreement for the upcoming season.
“Once those negotiations have concluded, they will address the potential clash for Welsh clubs in Round 1 of the LV= Cup, the dates of which were agreed by all LV= Cup stakeholders back in April 2014.”
Walesonline quoted a WRU spokesman as saying the Union was working with tournament organisers to resolve the issue.