WAILUKU, Maui — Maui County Mayor Alan Arakawa vowed to veto a measure that would set strict requirements for luxury developers to build affordable homes, despite the County Council's unanimous approval of the bill.

The bill requires developments in which fewer than half the units are to be sold for more than $600,000 to provide 40 percent of their units at affordable prices, defined as between $204,000 and $454,700.

No project would be allowed to have more than half its homes priced above $600,000 in a county where the median sales price for a single-family home hit $775,000 in September, then dropped to $647,500 last month.

Developers could satisfy the requirement by building the homes themselves for sale or rent, providing land for such homes or partnering with a nonprofit organization to build the cheaper homes.

Hotel and time-share developments also would have an affordable housing requirement.

Arakawa said it would hurt housing conditions in one of the nation's priciest markets, not help it.

Council members, who approved the residential Workforce Housing Policy on Friday, said it would be an important first step in providing more housing for local residents being squeezed out of the market by high prices.

Arakawa said he based his decision on concerns of developers, economists, bankers and other industry leaders who said the policy would halt new construction.

"We don't want a bill that will prevent affordable housing from being built," he said.

The council's support, however, indicates more than enough support to override an Arakawa veto.

"It doesn't matter. My job is to protect the community any way I can," the mayor said. "If the council overrides it, the council overrides it."

Some council members were angered by Arakawa's letter last week, in which he issued a "call to arms," asking the business community to express their opposition to the bill.

Arakawa said council members were motivated politically to support the policy, in order to boost his opponent in his re-election race, council member Charmaine Tavares.

"The only person who's made this political is the mayor," said council member Michelle Anderson.

She said the bill would be an important step in promoting social and economic equality on Maui, because it would ensure homes for local residents who can't compete for homes against millionaires.

Real estate broker Carol Ball said the requirements were too high, and the policy would not result in the construction of affordable homes.