The government's decision to move forward with Auckland light rail is nothing more than a "dream", the National Party says.
The government has chosen to build a half tunnelled - half surface light rail system from the city centre to Auckland Airport. It will run from Wynyard Quarter to Mt Roskill before surfacing and running alongside SH20 to the airport.
The option - which would cost about $14.6 billion - was recommended by the Auckland light rail establishment unit.
National infrastructure spokesperson Simon Bridges said the project was wasted spending.
"Today we hear the government is going to spend another $50 million on a business case. That's $100m of taxpayers' money spent before they've even got spades in the ground.
"If it ever goes ahead it will be at least $15b of wasted spending. Their light rail dream is just that - a dream."
Transport spokesperson Simeon Brown said the project's plan had been through so many iterations Aucklanders had given up believing it will happen.
The government should prioritise a second crossing over the Waitematā Harbour, Brown said.
"Aucklanders are sick and tired of this government trying to sell light rail in multiple different ways and that's just the latest iteration.
"What we need is a second harbour crossing and that needs to be the number one priority for our city."
ACT's transport spokesperson Simon Court described the project as a "disaster."
"We've spent four years trying to figure out how to make a political promise from Jacinda Ardern work. In the meantime, we've seen billions of dollars moved away from road building, projects cancelled, rescoped and deferred, fuel taxes increased, and regions neglected. New Zealanders deserve better."
Green MP Ricardo Menéndez March said the party would prefer street-level light rail down Dominion Road.
"It's a missed opportunity to not have gone with surface light rail because it would have enabled us to complete the project faster and start reducing emissions sooner, as well as give people more options for how they get around our city."
It was time to get on with the project, Menéndez March said, so the government had to ensure the end result was accessible to all communities.