Israel Folau is attempting to return to rugby league at the end of the year to represent Tonga in Tests against Great Britain and the Kangaroos.
However, it is understood there will be a strong push by members of the board of the Rugby League International Federation to veto the move at an upcoming meeting.
The Tonga National Rugby League released a statement on Monday saying the former Storm and Broncos star and his younger brother John, who played eight NRL matches for Parramatta in 2015-16, had made themselves available for Mate Ma'a Tonga.
The announcement of Folau's return comes amid a bitter dispute with Mate Ma'a Tonga players, led by Andrew Fifita and Jason Taumalolo, who are demanding the resignations of TNRL chairman George Koloamatangi and secretary William Edwards.
The TNRL appointed former Kiwis coach Frank Endacott to take charge of the team after sacking Kristian Woolf but it is understood that he is struggling to convince players to turn out in the October 26 Test against the Lions or the Oceania Cup clash with Australia on November 2.
Former Gold Coast Titans coach Garth Brennan will oversee Tonga's preparations for the World Cup 9s at Bankwest Stadium on October 18 and 19 but it is also unclear what sort of line-up he will have at his disposal.
The Folau brothers will not play at the World Cup 9s as NRL CEO Todd Greenberg and ARLC chairman Peter Beattie have made it clear that Israel was not welcome to return to the code after his contract was terminated by Rugby Australia due to a homophobic social media post in April.
Beattie is deputy chairman of the RLIF board, while Greenberg is one of seven other directors, who also include NZRL chairman Reon Edwards and CEO Greg Peters.
Despite claims by the TNRL and Folau that the RLIF had approved him to play for Tonga, NRL.com was told that no application had been made and the issue is set to be discussed during a phone hook-up of directors.
"The RLIF has made no decision in relation to any registration request for Israel Folau," Beattie said.
"As a current member and Deputy Chair of the RLIF board, as the ARLC representative, I can assure you that this has never been discussed or mentioned around the board table."
The RLIF issued a statement on Monday night.
“The Rugby League International Federation is aware of a media release issued by Tonga National Rugby League stating that Israel Folau has been ‘approved’ by the RLIF to represent Tonga in international matches," the RLIF said.
"That statement is incorrect, the RLIF has not been formally asked to consider this matter. The RLIF will not be commenting further on this situation at this stage.”
Both Israel and John Folau have been playing rugby union in recent seasons for the Waratahs.
Israel also represented the Wallabies before his contract was terminated and he is in the midst of a court dispute with Rugby Australia, seeking a multi-million dollar sum in lost wages following his sacking in May.
Folau played eight Tests for the Kangaroos from 2007-09. His last season in the NRL was 2010 and he played 91 games during stints with Melbourne and Brisbane, scoring 73 tries.
“I don’t want to bring any of my personal matters into this and I am grateful that the RLIF have endorsed my availability,” Folau said in the TNRL statement.
“What I will do now is focus on playing great rugby league and do my talking on the field.”