World Rugby's (WR) proposed Nations League is expected to come to an unsuccessful end amid extensive opposition to the annual tournament.
WR chairman Bill Beaumont will host a summit in Dublin overnight, attended by representatives from all tier one countries plus Fiji and Japan, as well as the international players' union.
The challenge he faces is convincing the Six Nations unions to abandon Project Light, the pooling of TV rights from the Championship and the autumn Tests to drive up revenue, in favour of the three-tier Nations League.
However, that would involve introducing promotion and relegation to the tournament, a possibility some unions including Ireland steadfastly oppose.
Strengthening the Championship's position is the funding raised if a substantial offer for a minority stake from private equity firm CVC Capital Partners is accepted.
A Six Nations source states the CVC money is not needed to bring Project Light to fruition and there are several commercial options being explored.
Beaumont will argue the revised Nations League, which has been altered in response to feedback, will grow the global game and knit together the fixture lists in the two hemispheres culminating in an annual final.
Cash-strapped New Zealand, Australia and South Africa can't compete with wages offered by French and English clubs and support World Rugby's vision for greater international depth in hopes of securing greater funds.
All tier one nations must vote in favour for it to be given the green light, however, and that scenario is highly unlikely with the Six Nations unions instead defaulting to financial self-interest.
Project Light - with or without the CVC money - will deliver superior returns.
World Rugby, who was mandated by the unions to investigate the viability of an annual competition, argue this is a short-term outlook on growth due, with the blocking of promotion and relegation reducing competitiveness.
No decisive outcome is expected from the Dublin meeting as the proposals must be taken back to various boards and voted upon but it is almost certainly the final attempt to advance the case for the Nations League.