UPDATED 3.27pm: Auckland's being told to get going on a roading plan now, or see the gridlock get a whole lot worse.

An independent advisory body is giving the city a choice between higher rates and fuel taxes, and new motorway tolls to fill a $12 billion funding shortfall.

Chairman Stewart Milne says a funding agreement is urgently needed to prevent the city from grinding to a halt.

He says roading projects take a lot of planning, and as time goes by things will get worse.

Stewart Milne says there needs to be political consensus about how to fund the city's transport network.

Proposed Auckland road toll may not fly

Mayor Len Brown is expected to announce a motorway toll of about $2, under a congestion-busting plan to plug a $12 billion-plus transport funding gap over the next 30 years.

But former Transport Minister Steven Joyce told Newstalk ZB's Mike Hosking Auckland Council needs the Government's approval for road tolls and that's highly unlikely.

"We're certainly not interested in regional fuel tax and we would have to be massively convinced about some form of toll and we'd have to be convinced that it was actually going to have a real beneficial impact for the cost on Auckland consumers."

Joyce says it is highly unlikely the Government will ever agree to allow tolls.

"The problem in this situation is actually the projects wouldn't make any difference. I think if you said to Aucklanders you could pay a toll but act you won't notice any major difference."

Truckies up in arms 

Truckies are asking what right Auckland's Mayor has to propose a two dollar toll on Auckland's exiting motorways to fund his transport wish list.

Road Transport Forum Chief Executive Ken Shirley says Aucklanders have already paid for these motorways through the National Land Transport Fund.

Mr Shirley says the other option, of a regional fuel tax, is also unrealistic.

Instead he's suggesting the Council sell the billions of dollars of assets it's sitting on, including its shares in Ports of Auckland and the International Airport.

Mr Shirley says the Mayor may be opposed to asset sales but hard decisions and trade-offs need to be made. 

Labour gives tolls the red light 

Labour's saying no to the Auckland Council's idea of imposing tolls on the city's motorways.

Labour MP Phil Twyford is labelling the idea a traffic jam tax and says it has to be given a red light.

He says Aucklanders already pay for roads twice; via road taxes, and via sitting in traffic.

Mr Twyford says they shouldn't have to pay hundreds of dollars more just to use a motorway.

Greens want open debate

The Greens want all options on the table, including cancelling motorway projects, when it comes to paying for Auckland's transport projects.

Green MP Julie-Anne Genter says there should be an open debate on funding but it shouldn't be restricted to funding.

She argues what should be funded should also be on the table including fewer expensive roading projects

AA: "People need to see the benefits first"

Meanwhile, the Automobile Association says people need to see the benefits of any new road charges before they can buy into Auckland Council's proposal for a road toll.

AA spokesman Barney Irvine says its members are concerned about paying extra for transport.

"If they are going to place new tolls, they're going to need to see exactly what they're getting in return in terms of their de-congestion benefits, in terms of travel time savings and in terms of increased mobility."

Irvine says Auckland Council's proposal for road tolls will have to be scrutinised carefully.

"What our members have made clear to us is that they really want to, and really need to, see the benefits of any charges."

Auckland Chamber of Commerce: "It needs to be done"

It might be costly, but the Auckland Chamber of Commerce says funding the city's transport needs to be done.

Chief Executive Michael Barnett says the Auckland Council's two options are the only solution.

"I think it's a distortionary. I think the fairest way of doing this is a motorway user charge. It hits the users rather than hitting 500,000 ratepayers, which to my mind would be the worst of the two options."

Barnett says there's no reason ratepayers should carry the cost.

"There is no other solution, we need to do this and the options available to use are rates and shore charges or a motorway charge, and probably a motorway charge is going to be the fairest of all of those."