PORTLAND, Ore. -- Republican Sen. Gordon Smith aligned himself with Democratic presidential candidate Barack Obama in a new ad Tuesday, stirring controversy in Oregon's senate race.

The ad, responding to attempts to tie Smith to high gas prices, credits Obama with saying that "Gordon Smith led the fight for better gas mileage and a cleaner environment." It may be the first time in this election cycle that a GOP Senate candidate has aligned with Obama.

There's just one problem though. Obama's campaign spokesman Bill Burton said Obama backs Smith's opponent, Democrat Jeff Merkley, for Senate.

"Oregonians should know that Barack Obama supports Jeff Merkley for Senate," Burton said in a statement e-mailed to FOX 12.

Matthew Miller, a spokesman for the Democratic Senatorial Campaign Committee, said Obama and Smith worked together on the 2006 fuel efficiency bill, but Obama never called Smith a leader.

Lindsay Gilbride, a spokeswoman for Smith's campaign, responded with the following statement:

"The ad -- more importantly the bipartisan legislation -- speaks for itself. It’s an unfortunate statement about politics in Washington today crossing party lines to solve problems is in any way controversial or something either party would oppose."

Smith is trying to keep his seat in a state that's been tilting toward Democrats. Polls still show him leading Merkley.

Gordon Smith Cites Work With Obama In Ad

Watch The Smith Ad Below: