Auckland councillors have rubber-stamped a $28.7 million cruise ship terminal on Queens Wharf without a proper report on the project.

Mayor Len Brown has kept councillors and ratepayers in the dark about the terminal, which the cruise ship industry and economic forecasters Covec have said could be built for $6 million to $10 million.

In June, Mr Brown broke a promise to consult Aucklanders on options for a cruise ship terminal, making a unilateral decision to go with Shed 10 on Queens Wharf.

He never consulted councillors on the decision, nor has he given councillors or ratepayers any details in public of the $28.7 million project, developed behind closed doors by Waterfront Auckland.

At a full-day council budget meeting yesterday, council chief executive Doug McKay and Waterfront Auckland chief executive John Dalzell gathered a cash breakdown of the project when it became apparent councillors planned to challenge the costs.

Mr Brown said the cruise ship terminal was about wanting Auckland to be a destination, saying the council was allowing public consultation on the proposal as part of the 10-year budget.

Councillors Mike Lee and Ann Hartley, who voted for the project, said the terminal would be a public space outside the cruise ship season and expressed a widely held view that Waterfront Auckland should avoid "gold-plating".

At the same meeting, Mr Brown voted against an extra $12.5 million over the next two years for upgrading sports fields, which has been the subject of extensive public reports and approval from a council forum and council committee.

Mr Brown said he could not support the extra funding, saying "prudence and affordability" were key parts of his budget.

Cracks also began to appear yesterday over funding for the $2.4 billion city rail link with a suggestion of selling shares in Ports of Auckland and Auckland Airport to help fund the project.

The council has near unanimous support for the link that Mr Brown calls a game-changer, but concerns are bubbling away about the huge cost and how to fund it.

Mr Brown expects the Government to pay half, motorists 30.9 per cent through tolls and congestion charges, ratepayers 16.6 per cent and development contributions 2.5 per cent.

Councillor Christine Fletcher - a former National cabinet minister - supports the rail link but said she wanted the council to consider selling up to 49 per cent of its 100 per cent stake in Ports of Auckland and selling down the council's share in Auckland Airport from 22.7 per cent to 10 per cent.

Speaking at the budget meeting, Mrs Fletcher said she did not think the Government would come to the party in the short-term and proposed the partial share sale as a contingency plan to gain credibility on the project.

She got backing from councillors Cameron Brewer and George Wood. Mr Brown said the rail link was the number one project in his 10-year budget and a test case of transformational change in Auckland.

The mayor - a Labour Party member - has promised not to sell shares in the port or airport.