"The Māori Party recognises the importance to New Zealand of increasing housing supply and the essential role that the RMA plays in supporting development in the areas where it is needed most - Auckland and Christchurch.
"However this should not be at the detriment to this country's natural and cultural taonga.
Once passed into law, the reforms will allow homeowners to carry out minor renovations such as extending their deck or building a fence without a resource consent.
They will also force councils to prioritise housing developments and to involve iwi more in the planning process.
ACT AND UNITED FUTURE
Earlier today, United Future and the Act Party restated in an open letter that they would support the reforms if National agreed to three concessions.
They want proposed powers for the Environment Minister to override councils to be scrapped; greater recognition of property rights, and the exclusion of iwi consultation requirements.
National needs two votes to get the reforms over the line.
It struck a deal with the Maori Party last year after agreeing to include provisions that would give iwi a greater role in the consenting process, known as iwi participation agreements.
However, the Maori Party then threatened to pull its vote unless the Government scrapped the ministerial override powers, which United Future and Act also oppose.
The Maori Party was especially concerned that the powers could be used to stop councils from creating their GE-free zones in their regions.
That leaves National facing an embarrassing defeat on one of its major pieces of legislation.
United Future leader Peter Dunne said he and Seymour were "trying to offer a way through" the stalled reforms.
"We are concerned that this impasse, which is now nearly 4 years old cannot go on indefinitely."
He believed that iwi involvement in the consenting process could be addressed through the existing principles in the RMA, and did not need a separate mechanism.
Seymour said the two leaders had "buried our considerable differences" to come up with an alternative for National.
"We're tired of waiting. We all campaigned on some degree of RMA reform at the last election. It's time for it to happen.
"But if the National Party thinks that [iwi participation agreements] are more important than getting through this set of RMA reforms, then I think they've made a serious misjudgment."