National convention centre bidder Ngati Whatua has attacked opponents and defended its choice of an Auckland site.

Tiwana Tibble, chief executive of Ngati Whatua o Orakei Maori Trust Board, said opponents were trying to undermine his bid for a national convention centre near the Vector Arena, claiming the site was too far from hotels and the CBD.

"For example, there is the '10-minute walk' myth being lobbied around Wellington that says the proposed new Government-funded convention centre must be within a 10-minute walk from major hotels. It first appeared in the Request for Expressions Of Interest document produced by the Ministry of Economic Development," Tibble said.

Ngati Whatua wants to build on land near the Vector Arena and hotels would be developed around the area.

"The city is constantly changing and so to make decisions based on how things are today seems a little silly," he said.

He criticised The Edge bid near Aotea Centre and SkyCity's proposal for 101 Hobson St.

The Edge is promoting the convention centre to be an expansion of the Aotea Centre, while SkyCity wants it to be its facility next to its casino.

"We see the Aotea Centre option as jamming an add-on into an already boxed-in site, on to an already uninspiring grey concrete building that is viewless and cold."

"We see SkyCity as the Tower of Babel option." The centre, he said, should be developed on flat land.

Officials at ASB Showgrounds this week revealed details of a $229 million convention centre proposal.

Traffic and accommodation were dismissed as problems: a $100 million hotel could be developed there and the business already hosted dozens of large events annually so had expert traffic management in place, said showgrounds chief executive Mark Frankham.

Coaches would take people from city hotels and Auckland International Airport to Greenlane, he said, and this was a strategy already in place for some of the bigger events being run at Greenlane.

He said the showgrounds worked closely with coach and taxi businesses and were close to main arterial routes including the motorway.

* SkyCity: 101 Hobson St opposite casino.
* Ngati Whatua's land near Vector Arena.
* The Edge alongside Aotea Centre.
* ASB Showgrounds on Greenlane land.
* Waterfront proposals at foot of CBD.