Sir Bob, who was Mayor of Waitakere City when the so-called eco-city entered the inaugural competition, said the odds of Auckland winning were very good.
The city's nomination has the support of Mr Key, Samoan Prime Minister Tuilaepa Lupesoliai Sailele Malielegaoi, Ngati Whatua's Joe Hawke and international cities expert Greg Clark, a longtime follower of Auckland's development.
Mayor Len Brown, who last year led a six-strong council delegation to the World Cities Summit in Singapore that oversees the prize, is another keen advocate.
"The prize gives Auckland the opportunity to show the world we are now a global city and want to be the best at what we do," Mr Brown said.
Mr Brown is attending a World Cities Summit mayoral forum in New York next month, ahead of the shortlist being drawn up.
Council chief planning officer Dr Roger Blakeley said a big pitch for Auckland was the move to a Super City with one council, one mayor and one plan for the city.
Design-led projects, such as Wynyard Quarter, Britomart and shared spaces, the city's diverse population, and Maori and Pacific cultures were other selling points.
The council has budgeted $70,000 this financial year to research and prepare a report and supporting material for the competition.
If Auckland advances to the shortlist, the council will spend up to a further $60,000 for additional presentation material and Mr Brown and a delegation travelling to Singapore to collect the prize.
Funding for the competition is coming from existing budgets in the mayoral office and planning division.
World City Prize
• Lee Kuan Yew World City Prize held ever two years
• Honours creation of liveable, vibrant and sustainable cities
• Organised as part of biennial World Cities Summit in Singapore
• $285,000 cash prize
• Previous winners include Bilbao, New York and Suzhou in China