“Seeping sewage into our pristine lakes like Taupō” is the picture embattled Local Government Minister Nanaia Mahuta painted as she for the last time sought to rally support in Parliament for the controversial Three Waters reforms.

Backed by Labour with its majority, the Water Services Entities Bill passed its third and final reading today, despite opposition from each of the four other parties from all sides of the political spectrum.

It passed amid a fiery debate with National and Act MPs, who have opposed the reforms vehemently throughout the process, giving it one last shot to paint their own picture of rushed and ineffective legislation, and railing against removing assets from local councils.

They have both vowed to repeal the law if they hold power after the 2023 elections.

The Greens supported most of the reforms but held off their support due to concerns about a lack of protections from privatisation.

Meanwhile, Te Pāti Māori opposed, saying despite claims from both sides of the House it did not implement co-governance and tino rangatiratanga had been ignored.

The bill is the first of three as part of the reforms, aimed to ensure affordable drinking water, wastewater and stormwater services are available across the country.

Mahuta started her speech by focusing on the root issues the law was designed to address, the boil water notices, no swim notices and regular burst storm and wastewater pipes all over the country.

“Seeping sewage into our pristine lakes like Taupō, happens... In a country like ours this is just not good enough.”

She spoke of climate change and added pressure it would have on ageing infrastructure.

• Calls for Nanaia Mahuta to be fired for her role in Three Waters entrenchment
• David Seymour on Govt's reversal on Three Waters entrenchment

Mahuta said centralising the water infrastructure would reduce costs on local councils, and in turn, keep rates down at a time of rising cost of living pressures.

She said the Government was fixing a legacy problem “left to languish the last two decades”.

She also took a dig at the Opposition and how it did not support measures to ensure water assets could not be privatised.

“This Government is 100 per cent committed to ensuring our water assets remain in public ownership, and we call on the Opposition to make the same commitment to New Zealanders.”

National Party local government spokesman Simon Watts meanwhile reiterated he and his colleagues were “strongly opposed” and would repeal the law if elected in 2023.

As he began the North Shore MP was heckled by Labour MPs, Cabinet Minister Peeni Henare calling out “You cannot swim at the beach on the North Shore!”, referencing the regular sewerage overflows.

Watts said the reforms were one of the most controversial in recent times, referencing the 88,000 submissions with the majority opposed.

“Most mayors and councils across this country support the need for reform, to improve water infrastructure, but strongly oppose this bill as a means to achieve those ends.”

He said National would come up with its own solution that would “achieve the desired outcomes for our communities without the loss of control and complexity that this Labour water services entities model brings”.

The Three Waters programme would take water assets like pipes and reservoirs from 67 councils and amalgamate them into one of four massive water entities.

The councils will own these entities through a shareholding and will co-govern them with mana whenua.

Due to earlier opposition to the reforms, the Government brought together nine mayors and nine iwi representatives to find their own solutions, in the end accepting nearly all the group’s 47 recommendations.