OLYMPIA, Wash. (AP) - Although bags full of mail-in ballots remain to be counted, tax rebel Tim Eyman is declaring victory for his initiative plan to create tough new rules for tax hikes in Olympia.

Initiative 960 led 52 percent to 48 percent as of early Wednesday with 43 percent of the vote counted, leading in all but five of the 39 counties. Opponents held out a possibility that later tallies from liberal King County could turn the tide.

An ecstatic Eyman, who had prepared for a narrow defeat, declared an "enormously gratifying" victory and said he'll soon go public with his 2008-model initiative.

"This is very, very cool," Eyman said in an interview. "I'm really confident we will chalk up another victory for the taxpayer.

"Obviously with these numbers we're confident we're going to put it over the top. We won despite not spending a penny on paid advertising or a media campaign - no yard signs, no buttons, no T-shirts. "The other side had over a million dollars, lots of it from out-of-state special interests. This is enormously satisfying."

Christian Sinderman, a longtime Eyman adversary and spokesman for the opposition campaign, said the numbers were discouraging, but that many votes were left to be counted this week in King County, which includes Seattle.

The measure was failing badly in King, 56.4 percent to 44.6 percent, and also trailed in Jefferson, San Juan, Thurston and Whitman counties.

"We'll wait a couple of days to see how the vote does," he said.

A constitutional challenge in the courts is likely, Sinderman said.

"Regardless of how this turns out, Olympia is going to have difficulty going back to business as usual," Eyman said in an interview.

"The public has a much greater understanding of the Legislature's repeated abuse of the emergency clause and its negation of our constitutional rights" to challenge tax votes by referendum, Eyman said.

He referred to the Legislature's long-standing practice of attaching an emergency clause to bills so they take effect upon the governor's signature, foreclosing a ballot challenge by referendum.

Eyman, loathed by Washington's Democratic political establishment, but lionized by conservative small-government forces, offered voters new wrinkles in his fight against taxes.

Initiative 960 sought to strengthen the state's two-thirds approval requirement for tax hikes in Olympia, and to add new requirements for public advisory votes, legislative approval of all new state fees, and a heavy flow of information on all tax and fee measures.

Eyman, who operates the state's busiest initiative factory, has pushed 15 in the past decade, winning ballot spots for 10 and voter approval of seven. His initiatives rolled back car-tab taxes and affirmative action programs, limited property taxes and created the country's most sweeping program of government performance audits.

He returned to his tax-rebel roots with I-960, framing it as a way to rein in taxes and give voters more information and a stronger voice.

Key points of Initiative 960:

-Affirm, and somewhat expand, the two-thirds voting requirement for the Legislature to pass tax hikes. Taxes passed with only a simple majority would have to go to the ballot for ratification.

-Require a flood of information on all tax and fee legislation, including 10-year cost estimates.

-Require lawmakers to vote on every fee increase, rather than delegate authority to the agencies.

-Require a nonbinding public vote on taxes passed in Olympia with an emergency clause - a tactic that precludes a referendum campaign to overturn the tax.

Eyman said in a pre-election interview that I-960 would provide "adult supervision" of lawmakers.

"Olympia gets really dangerous when they don't think people are watching," he said. "We think they'll do the right thing if they know the press and public are watching."

However, foes said the measure threatened to handcuff elected leaders with expensive and needless barriers to financing the very services that voters need and demand.

Gov. Chris Gregoire, House Majority Leader Lynn Kessler, D-Hoquiam, and other leaders said the initiative undermines representative government. Gregoire described I-960 as unnecessary, costly and counterproductive.

The state budget office estimated that the additional disclosure requirements and election costs would average about $1.8 million a year.

Environmental groups, education advocates and others opposed it and helped finance a $1.2 million opposition campaign, while Eyman relied on free media.