Auckland Mayor Len Brown is accusing the Government of jumping its own gun in trying to veto alternative funding such as road tolls for congestion-busting transport schemes.
He says it should wait until its officials complete a joint analysis with Auckland Council staff of the $2.86 billion underground railway proposal.
Mr Brown warned Local Government Minister David Carter that scrapping such projects from the regional transport strategy would have "a dire and unacceptable" consequence for congestion in the country's commercial capital.
Next in priority are $2.2 billion of upgrades through southeast Auckland, including a freight highway from Mt Wellington to Onehunga, and a third Waitemata Harbour crossing for more than $5 billion.
In a letter to the minister, Mr Brown has described as "entirely premature" a Government statement that it does not support assumptions in the new 30-year Auckland Plan about extra revenue sources to fill a transport funding gap of $10 billion to $15 billion.
"We are in the middle of a thorough joint assessment in relation to the CRL [rail link] and near the start of a process to consider alternative revenue sources that will not be concluded until the adoption of the 2015 Long Term Plan," he said.
That refers to an Auckland Council decision to establish a "consensus building group" to focus on road tolls, a regional fuel tax and higher parking charges while also keeping in mind options such as tourism levies.
But Transport Minister Gerry Brownlee says it is ridiculous for the council to think it can use taxpayer-funded roads to raise its own revenue, and has poured cold water on more fuel tax.
A poll of more than 1000 Aucklanders conducted for the Council for Infrastructure Development has meanwhile found higher support for road tolls to fix congestion and rail transport funds from National than Labour voters.
National voters indicated 66.8 per cent support for tolls, compared with 56.3 per cent of Labour backers.
Support in principle for tolls
Overall - 63.8 per cent
Party voter support
* Act - 88.6 per cent
* Mana - 76.1 per cent
* National - 66.8 per cent
* NZ First - 65 per cent
* Greens - 60.9 per cent
* Labour - 56.3 per cent
* United Future - 51.8 per cent
* Maori Party - 25.3 per cent
Source - Horizon Research survey of 1061 Aucklanders. Margin of error of 3.1 per cent.