Tonga is poised to challenge the ruling which has deemed NRL duo Fuifui Moimoi and Taniela Tuiaki ineligible to play for the Pacific Island nation in the World Cup.
Parramatta's Moimoi and the Wests Tigers' Tuiaki were selected in Tonga's 24-man squad for the tournament, which kicks off later this month, but the Rugby League International Federation (RLIF) ruled that the duo cannot take part after electing to play for New Zealand last year.
Under RLIF rules, players who are eligible to play for more than one country can make one application to switch their allegiance in any two-year period.
"Players who are eligible to play for more than one country must elect which country they will represent," an RLIF statement said.
"A player is allowed only one application under this rule in any two-year period."
It was a major blow for Tonga, who had already lost Anthony Tupou to Australia following re-classification and it is now assessing its options.
Tongan tour manager and director William Edwards said in the Sydney Morning Herald: "My board has informed me they have engaged legal counsel and will take the matter before the courts."
"They are being denied their right to play. My board have taken the view that Fuifui and Taniela should be wearing a Tongan jersey."
Tongan coach Jim Dymock had approached his New Zealand counterpart about selecting the duo and had been given the go-ahead.
"I just don't understand," Dymock said in the Sydney Morning Herald.
"I've spoken to Steve Kearney and he's more than happy for them to play for us. I don't see where the damage is. It's not hurting New Zealand. I don't know who it's hurting."
"More than anything, we've got two quality players who will be sitting in the grandstand when they could've been helping out an emerging nation."
RLIF chairman and tournament director Colin Love sympathised with Dymock but insisted the rules must be applied.
"We'd love to see all the best players in the tournament," he told the Sydney Morning Herald.
"But you can't just break the rules, you can't turn it into a farce."