Leader Unasa Iuni Sapolu will be campaigning to have the Land and Titles Registration Act 2008 removed.
Under the act, Ms Sapolu said the Minister of Natural Resources can lease customary land without the owners having to provide informed consent.
She said this was illegal.
"Who is controlling the land? Obviously the leaseholder who is the Minister [and] has his power been legitimatised by the customary land owners?"
She said the answer was "no".
"That move, in my view, is a violation of the constitutional right of the customary land owners."