The memo came from Auckland Council's economic development body Ateed, which developed the 10-year visitors plan. Executive Rachael Carroll told councillors visitor plan targets were tied "specifically" to SkyCity's plan to build the centre. She said growth targets projected a budgeted increase in convention spending from $92.8m to $206.7.
"The majority of required growth in international delegates is pegged to the opening of a National Convention Centre in 2015," she wrote.
Mrs Carroll also warned accounts were "at risk" because the convention centre would not be open by 2015. Delays would continue to have "significant negative implications" on targets.
The papers also show the council was called on to brief the Government over the chances of SkyCity getting resource consent for the centre.
It put forward regional planning executive Penny Pirrit, who told the Government the plan faced a tough battle to get consent.
She said there were issues around the proposed architecture, raised by urban design champion Ludo Campbell-Reid. Pirrit said the SkyCity plans were not seen as having the "wow" factor and it was not an iconic building - "rather it reflects much of the existing SkyCity complex in relation to design".
She said increased foot traffic from the convention centre "will provide added weight to the business case for the CBD rail loop". However, the air bridge sought by SkyCity to connect the convention centre to the casino posed a problem, she said. Council rules opposed air bridges unless the public could be shown to benefit and safety was an issue. The decision lay with the council, she said.
A spokesman for Mayor Brown said the final design for the centre had yet to be received. The council had also not yet received a resource consent application.
Green MP Denise Roche - a former Auckland City councillor - said support for the SkyCity proposal in the visitor plan was probably "slipped past" the council. Councillor Cameron Brewer said the councillors opposing the deal were the same who had previously pledged to back it.
"They can't have it both ways. They signed off on the visitor plan and all its aspirations and so they now need to get in behind and support the convention centre and not play party politics just because they don't like the National Government."
Mrs Carroll said it was her job to brief the council on issues affecting the visitor plan, leading to the memo.
She said delays postponing the expected opening in 2015 had already cost Auckland $200 million in visitor income.