London Broncos co-owner Darren Lockyer has called on English clubs to seize a "once in a generation" chance to reshape the sport alongside the NRL.
The Broncos are expected to join Super League's top division under the proposed agreement, giving Lockyer a direct interest in the negotiations.
The five-year investment package is reportedly worth £50 million (AUD$95 million), with approximately £6-7 million annually flowing directly to Super League clubs.
However, UK reports identify Leeds Rhinos and Bradford Bulls as the only two clubs among Super League's 14 teams yet to support the proposal.
Leeds are coached by Brad Arthur, while the reasons for both clubs' hesitation have not been made public.
The unresolved issues reportedly concern the English competition's governance and the method used to distribute the NRL's funding.
Any final agreement may therefore depend on how much control Super League clubs retain and whether the NRL offers further concessions.
Incoming St Helens coach Kevin Walters has questioned whether the English competition requires urgent assistance, despite his new club supporting the partnership.
"I don't think Super League is in need of help, that's not what I see," Walters told BBC Sport.
His view aligns with St Helens chairman Eamonn McManus, who has described the arrangement as a partnership rather than an NRL takeover.
Lockyer said, "Super League is a great product, but it really does need a shot in the arm… the NRL can provide that,"