Regional Rugby Wales (RRW) relinquished its seat on the board of Heineken Cup organisers ERC at the height of the European rugby impasse.
Now the WRU wants RRW to appoint a replacement for Stuart Gallacher, who stepped down from the ERC board last month, in time for that nominee to attend Wednesday's meeting in Dublin.
Welsh union bosses confirmed in a statement they had written to RRW on Tuesday, urging the Welsh regions conglomerate to send a representative to the ERC summit.
This latest move from the WRU would seem to cloud both the European wrangle and the Welsh civil war still further.
English club body Premiership Rugby and Welsh counterpart RRW want a new European competition for next season to fall under the governance of the Six Nations organising committee.
The WRU has now nailed its colours to ERC's mast, aligning itself with the Irish provinces and the Irish rugby union.
Representatives from the six European unions and club bodies were meeting on Tuesday near Heathrow Airport in London.
This latest bid to thrash out a way forward for top-flight European had been hoped to bring real progress with it.
But now it seems the WRU could have put itself on a collision course with Premiership Rugby and RRW over tournament governance once again.
Chief executive Roger Lewis has also told BBC Radio Wales the WRU must remember its contractual obligations in the European wrangling, another intimation of a preference towards ERC.
"Europe is a sum of many moving parts, it's not just a discussion between ourselves and the four regions," he said.
"We have to recognise the contractual positions that we've all arrived at and we have to recognise our responsibilities and liabilities to the stakeholders who, legally, we have entered into contractually binding arrangements with."
- Premiership Rugby