The loop is projected to cost $2.4 billion.
Auckland City would have to pay half, and a Goff lead government would pay the other half by cancelling a "holiday highway" north of Auckland.
Goff said to become the world class city Auckland wants to become, it needs a world class transport system.
The current western and southern motorways were "bloody nightmares" he said.
Labour wanted to support Auckland Mayor Len Brown's plan for an inner city underground rail loop which would double the amount of trains the Britomart transport system could handle.
He attacked Transport Minister Steven Joyce, saying he was "mesmerised" by motorways and was planning to build a $1.7 billion motorway from Puhoi to Wellsford, which would link popluar beach destinations". Stuff.co.nz
The only problem with this proposal is that the 2.4 billion price tag is conservative, barely 2% of Aucklanders use trains and over the life of any proposed system the loop and its extension will lose billions more dollars that Aucklanders and Kiwis simply don't have.
Another major drawback is that motorists will be subsidizing rail through increased petrol taxes, road tolls and congestion charges.
Put simply it may have been a good idea 2 -300 years ago but technology as it is now means a rail loop and expanded rail network is expensive, uneconomic, polluting, inefficient and will not solve any current or future perceived transport problems.
Add to this that Labour want to ditch the long needed Northern motorway extension to help fund the government's share under their proposal and you clearly have a lose lose, situation.
The extension north will save lives, be a boon for trade between Northland and Auckland and the rest of the North Island and provide a much needed stimulus to a long-lagging Northland economy.
Labour want to ditch that in favour of a wet dream of train-tracks crisscrossing Auckland that will be a white elephant that ratepayers and taxpayers will be paying for dearly as long as it exists.
We need fiscal restraint at this time, not pork barrel politics and favours for mates.