OLYMPIA, Wash. -- Washington Gov. Chris Gregoire's big biodiesel campaign bus has Oregon plates.

State Republican Chairman Luke Esser, who brought it to reporters' attention Thursday, says it's a symbolic reminder that Democrat Gregoire is throwing small businesses under the bus.

Gregoire used the bus as a photogenic part of her campaign tour of 10 cities this week. The GOP is circulating photos that show Oregon plates on the big rig and also British Columbia tags on the front.

Esser says Washington has one of the worse small business failure rates in the country, and that Gregoire isn't helping with missteps like that.

Debra Carnes, the governor's campaign spokeswoman, says the bus was rented from a Washington company.