Homebuilders have launched a telephone campaign opposing King County executive candidate Dow Constantine, while environmentalists are paying for a mailing that supports Constantine and attacks his opponent, Susan Hutchison.

The new ads bring independent expenditures in the executive race to $364,608, and more are likely to come.

That's in addition to record-setting fundraising by the candidates themselves. Constantine's campaign approached the $1 milliorn mark this week, reporting $958,551 in contibutions. Hutchison reported $675,258 to the state Public Disclosure Commission.

The Master Builders Association of King and Snohomish Counties' political arm, the Affordable Housing Council, this week reported a $17,500 telephone campaign in support of Hutchison, a former TV news anchor who now directs an arts and sciences foundation. The Master Builders also has given $50,000 -- the largest contribution -- to a JibJab-style TV ad parodying Constantine's record as a Metropolitan King County Council member.

"Our Affordable Housing Council views Susan to be the candidate of change who will bring an outsider's perspective to county government," Master Builders spokeswoman Allison Butcher said. The builders also view Hutchison as "the more pro-housing candidate," she said.

Constantine, meanwhile, is getting a boost from the Washington Conservation Voters Action Fund, which spent $15,000 on a mailing that calls Hutchison "vague and evasive on environmental issues" and describes Constantine as "an environmental champion."

We've previously reported on a $101,186 anti-Hutchison cable TV ad funded by the Service Employees International Union, other unions and abortion rights groups, and on the $164,500 anti-Constantine ad paid for by the Master Builders, Bellevue Square developer Kemper Freeman and others.