PORTLAND, Ore. -- Republican Sen. Gordon Smith's re-election campaign says it will remove Democratic Sen. Ron Wyden's signature from a TV ad after Wyden objected to its use.

Oregon Senator Ron Wyden. (AP Photo)

Smith, in a close race against Democrat Jeff Merkley, has used images of numerous Democrats in his ads, including Sen. John Kerry and Sen. Barack Obama.

Wyden's image and signature appear in Smith's most recent 30-second spot.

The ad, which shows an old clip of Wyden praising Smith, will continue to run but without the signature.

Smith and Wyden are known for their close working relationship but a recent Wyden ad goes farther than usual when it boosts Merkley's attempt to unseat Smith.

In past campaigns Wyden has endorsed Smith's Democratic opponents but has not appeared in ads promoting them

Wyden did not mention Smith in the 30-second spot, which began airing Thursday, hours before their first debate. The ad closes with a photo of Wyden and Merkley on stage together.

Wyden says in the ad that Merkley would work with him "to put the economy back on track."