Opponents of the $60 car-tab fee on the November ballot have filed a complaint with the Seattle Ethics and Elections Commission, charging that two bicycle-and transit-advocacy groups are using city money to campaign in support of the ballot measure.

City ethics rules prohibit city money being used to influence an election.

Citizens Against Raising Car Tabs says in its complaint that two non-profit groups, Cascade Bicycle Club and Transportation Choices Coalition, "improperly used taxpayer funds to substantially underwrite 'Streets for All Seattle,' the campaign promoting Seattle Proposition 1, which would fund city transportation projects.

In the complaint filed last Thursday, the opponents provided the ethics commission with copies of invoices showing that the Cascade Bicycle Club Foundation received almost $230,000 from the city for education and outreach from January 2009 through September 2011.

The Transportation Choices Coalition received $36,000 from the city to pay its membership dues, according to invoices provided to the opponents by the city in a public records request . Other government agencies including Sound Transit are also members of the coalition.

A spokesman for Cascade Bicycle Club says all the city funding it gets goes to its education foundation for public programs, including bike-helmet distribution, safety classes and summer programs for disadvantaged youth.

"Money for the campaign comes from our PAC that is funded by private donors. There's zero connection to any city contract," said Craig Benjamin, policy and government affairs manager for Cascade.

He called the ethics complaint "a frivolous waste of taxpayer money. We're confident it will be dismissed."

Wayne Barnett, executive director of the Ethics and Elections Commission, confirmed Monday that a complaint was filed, but couldn't comment on the merits. Because it involves an election issue, Barnett said it would be speedily resolved.

John Fox, an advocate for low-income issues and a leading opponent of the $60 car-tab measure, called lobbying by groups who receive city money "troubling."

"Whether or not it's an ethics violation," he said, "how do we know they did not use city funds to campaign?"