No.
The League (Super League) that will make that decision. The same as the NRL, they can refuse to register contracts. That's what came out the recent meeting in Salford, post link here:
https://forums.leagueunlimited.com/...urns-to-the-nrl.452657/page-121#post-13985723
I found that I needed to read past the first couple of paragraphs. The Clubs voted on it but the authority falls to Super League.
The Super League chief executive, Robert Elstone, made a statement following a four-hour meeting at Salford’s AJ Bell Stadium pleading for the focus to be shifted to the on-field action and away from Folau’s transfer. It stressed that measures are now in place for Super League to block such signings.
“The Super League board accepts the legalities around the RFL’s decision to register Israel Folau,” he said, “and the board has voted unanimously to put in place measures that ensure the Super League has greater authority to stop controversial signings such as this in the future.
Quite frankly, I'm surprised it wasn't already in place.