Danske Bank Premiership sides are reserving judgement on the proposal for an All-Island League with opinions on the issue divided within clubs.
League of Ireland Premier Division clubs have written to the FAI to ask them to send the proposal for the All-Island League to Uefa for consideration.
Ten of the 12 Premiership sides have forwarded a similar letter to the Irish FA, with Dungannon Swifts and Cliftonville declining the opportunity to request further information and analysis.
The Irish FA, in particular, are opposed to an All-Ireland League and their view is unlikely to change.
Many hurdles must still be overcome before the project can become a reality with northern clubs concerned about losing European places, falling attendances and the financial merits of the initiative, particularly at a time when the game has been badly disrupted by a pandemic.
Input from Uefa could either allay or confirm some of those fears. Champions Linfield did sign up to the letter but one Blues source said: "There are different views within the club. We were on board with the letter but have committed to nothing at this stage."
Uefa ratification would be required if the plans driven by Kerry businessman Kieran Lucid are ever to get off the ground.
The letter addressed to interim FAI CEO Gary Owens asks Abbotstown chiefs to "work constructively with the clubs, the IFA and Uefa" on examining the plausibility of this project.
After protracted discussions around formats and the airing of concerns around the impact on lucrative European places, Dutch experts Hypercube took the feedback of clubs in devising a format that won approval from the majority.
The format agreed via Hypercube would involve a split season with the League of Ireland and Irish League proceeding as normal for the first half of the campaign.
At an agreed cut-off point, the top eight League of Ireland sides and top six Irish League teams would go into the cross-border league that leads to a knockout series which results in a victor crowned King of the Island.
Points picked up during the league section of the all-island fare would also be added to the domestic tally with a view to deciding the finishing places that determine European spots.
Teams who miss the cut would also enter into new competitions with promotion and relegation issues at stake.
The intention is to preserve as many of the eight European places currently available for teams on this island as possible.
But that will all be determined by Uefa's formal view.