The Transport Minister and Cabinet went against Treasury advice by agreeing to announce an overhaul of Wellington's transport.

The final plan announced today for Let's Get Wellington Moving will cost $6.4 billion.

But documents show the Treasury cautioned Cabinet over making an announcement at this stage, saying it was risky.

It warned an announcement would raise public expectations before the costs and benefits of the package are fully understood.

Transport Minister Phil Twyford says Cabinet endorsed the plan because Wellingtonians have waited decades for transport investment.

He says he'll report back to Cabinet with a long-term financing proposal in due course.

I’m really proud of our urban designers who came up with this solution to ease congestion at the Basin Reserve.

It’s enduring and an addition to our cityscape, rather than detracting from it. Now it’s time to get on with it.

Picture two is what it could have been. pic.twitter.com/xeUsRFwvDu

— Justin Lester (@justin_lester) May 16, 2019

The package features cycling and walking paths, public transport investments, and mass transit, however, it does not include a second terrace tunnel.

Mayor Justin Lester admits that the tunnel is much sought after, but told Heather du Plessis-Allan that not everything from the initial proposal has been given funding.

"What we have got is $6.4 billion of committed funding in a package from the Government, and we want to get on with it today."

Lester rejects that the plan does not fix the traffic around Basin Reserve, as the new mass transit proposals will be the fastest and most regular routes. 

A second Mount Victoria tunnel has been included in the final package.