Two Maori trusts have applied to the Supreme Court for leave to challenge the sale of 16 North Island farms formerly owned by the Crafar family which are in receivership.
The groups are the Tiroa E and Te Hape B trusts, which are part of the south Waikato iwi Ngai Rereahu.
They had wanted to buy the 16 farms, totalling 7892 hectares, but lost to Chinese company Shanghai Pengxin.
They challenged approval of the sale in the Court of Appeal along with Sir Michael Fay, but lost decisively.
Sir Michael has since walked away, but the trusts are pressing on, saying some issues were not dealt with by the court and some which were considered were mishandled.
The Chinese buyers are confident the deal is safe.
An official at the Supreme Court says the applicants have 20 days to produce submissions and the respondents have 15 days to reply.
Judges will then decide whether the case has enough merit to proceed.