Top Pacific Islands stars will vote on whether to boycott the 2019 World Cup over World Rugby's controversial World League plans.
World Rugby is understood to be ready to omit Pacific Island nations Samoa, Tonga and Fiji from the 12-strong annual World League competition planned to launch as early as 2020.
The Six Nations Test teams and the Rugby Championship nations would be joined by Japan and the United States under World Rugby's latest considerations.
Promotion and relegation has been mooted to hand tier-two nations like the Pacific Islands and Georgia the chance to step up, but the competition could also be ring-fenced for 12 years at a time.
Pressure group Pacific Rugby Players Welfare (PRPW) has pledged to canvass its 600-strong membership on whether Samoa, Tonga and Fiji should stage a World Cup walkout - something chief executive Dan Leo believes would jeopardise the entire competition in Japan this autumn.
"The World Cup would lose: I don't think the competition could go ahead if you took out a quarter of the players," Leo told Press Association Sport.
"So that's the impact that we have. We don't have the commercial audience size that World Rugby wants to put into place for this competition, we don't have that.
"We are setting in place a vote of all our members over whether the Pacific Island nations should boycott this year's World Cup.
"We provide almost 20 per cent of all professional players in terms of heritage.
"And almost a quarter of the players at the next World Cup will be of Pacific Islands heritage.
"So that's where our strength lies, our strength in numbers, and that's how we can mobilise."
Leading players Owen Farrell, Johnny Sexton and Kieran Read all hit out at World Rugby's World League plans on Thursday, criticising the blueprint for five-straight top-tier Test matches every November from a player welfare standpoint.
The International Rugby Players' Council (IRPC) has stood firmly against World Rugby's new competition, but now Pacific Islands player representatives have taken several giant steps forward.
Leo's independent PRPW group has already joined forces with Pacific Rugby Players, the world's other Pacific players' group, over a possible World Cup boycott.
And now Leo has called on the Samoa, Tonga and Fiji unions to join their plans to rebel against World Rugby's plans.
"It is time for a legitimate player protest," said Leo.
"This would be a disaster for the Pacific Island nations, and for any nation omitted from the top 12 teams to be frank.
"Even if promotion and relegation were involved, all that would happen would be that the top teams would pull away from the rest.
"Now is the time for the voice of Pacific rugby to be heard through our players, so that we might head off this calamity.
"And we invite our national unions to join this collective effort to repel this proposal, before it is too late."
World Rugby suggested on Thursday that some expressing fears around their new competition plans were jumping to conclusions.
"World Rugby recognises and values the importance of player considerations and input into the annual international competition discussions," read the governing body's statement.
"World Rugby's commitment to player welfare matters is unwavering, and we will continue to engage and give full consideration to the welfare of players within the ongoing discussions.
"It is inappropriate to comment on specifics while wider stakeholder consultation is ongoing.
"However it is important to note that some assumptions made in the statement regarding the proposed competition structure are inaccurate, and that important matters such as playing load and emerging nation opportunities are at the heart of constructive dialogue on the overall concept."