World Rugby has insisted no firm decisions have yet been made about the proposed world league competition with tomorrow's Dublin meeting involving representatives from all tier-one nations, along with Fiji, Japan.
The idea has met with fierce opposition, most notably from player welfare groups, while the suggestion that the Pacific Islands nations of Tonga, Samoa and Fiji could be excluded has also provoked fury.
Their move comes as representatives from the major unions and player associations meet in Dublin to discuss plans to take the worldwide game forward with a meaningful test championship.
Representatives from the Premiership and Top 14, as with the Pro14, have not been invited, however, even though they would face losing some worldwide players for additional weekends.
The French and English clubs are unhappy at what they believe will be a heavier test programme in November and December that will impact their tournaments.
It is understood they are willing to pursue the matter through legal action if necessary.
But in a joint statement Premiership Rugby of England and their French counterparts, Ligue Nationale de Rugby, says their clubs feel World Rugby's proposal runs against what was agreed for a long-term vision at a meeting of major stakeholders in San Francisco in 2017.
"It appears that the new competition plan now challenges this balance by increasing the number of global matches, including among other periods extending into December with four or five successive worldwide weeks which had been specifically rejected for established annual worldwide competitions".
World Rugby believes otherwise, claiming the new format will mean an increase in matches only for the teams that qualify for the finals.