Initiative promoter Tim Eyman turned in plenty of signatures Friday for a measure that would reinforce a rule making it more difficult for the Legislature to raise taxes.

Eyman said more than 318,000 people signed petitions for Initiative 1185, which requires lawmakers to have a two-thirds majority to create or raise taxes. He said it's the most effective way for voters to send a no-tax message to Olympia leaders.

"Taxpayers desperately need protection from job-killing, family-budget-busting tax increases," Eyman said.

Voters approved the idea in 2010 with Eyman's Initiative 1053 and in 2007 with Initiative 960. He said it needs to be renewed every two years or lawmakers could ignore it in January. That's because the state constitution allows the Legislature to amend initiatives by a simple majority after two years.

Opponents believe the rules create gridlock in the Legislature by giving a small group of lawmakers the power to block tax increases.

"It's time for Time Eyman to get the word from voters: No already," said Doug MacDonald, the state's former secretary of transportation.

Initiatives require about 242,000 valid signatures from registered voters to qualify for the ballot. The secretary of state's office recommends that initiative sponsors bring in about 320,000 signatures as a buffer for duplicates and invalid signatures.

Election officials have already started reviewing the petitions to determine whether there are enough valid signatures. The check on Eyman's measure is expected to be completed in about three weeks.

While voters have showed strong opposition to new taxes, they did reject Eyman's proposal last year to restrict the use of tolling.

The two-thirds rule, meanwhile, is facing a legal challenge. A King County judge determined that the law is invalid because the state Constitution indicates that only a simple majority is needed for the passage of tax measures.

That court case is expected to be ultimately determined by the state Supreme Court. Eyman said he was confident the courts would uphold the rule.