Portland Mayor Charlie Hales concluded a heated hearing on his proposed "street fee" by challenging angry business owners and anti-tax activists to find a single wasted dollar in his city budgets.

The mayor then took to social media and repeated his challenge—which includes a cash reward.

Hales' tweet says:

"In response to pet project accusations: If you can find misspent money in my budgets, I'll show up on your doorstep with $10 & a TV reporter."

The dare comes in the wake of the latest in a series of increasingly contentious town halls on the street fee, which Hales and City Commissioner Steve Novick say would raise $40 million a year for transportation projects.

Hales and Novick delayed a vote on the fee last month after public backlash to their plan to charge households $144 a year and businesses much more. This morning's town hall is the first in a series of public meetings intended to get feedback on how to rework the fee.

On June 19, City Council approved a budget with $515 million in general fund spending. 

Happy hunting!

UPDATE, 11:35 am: WW asked Hales spokesman Dana Haynes what would qualify as a misspent dollar, since public opinion regularly diverges on budget priorities.

Haynes says the mayor was responding to to illegal spending. 

"The mayor gets pretty mad at veiled and not-so-veiled accusations of illegality in the budget," Haynes says, "which is poured over by the independent City Budget Office, the City Attorney's Office, the Multnomah County Tax Supervising and Conservation Commission, and the best press corps in the Northwest. His challenge: Find even one illegally spent dollar in his budget; the mayor dares you."