A federal judge in May stopped the investigation, saying that government can't regulate groups running issue ads that don't expressly support or oppose a candidate. Prosecutors are appealing.

Both Burke's campaign spokesman Joe Zepecki, and the Trek spokeswoman, said there was no coordination between the two over the newspaper ad. Trek's ad did not mention Mary Burke by name or call on voters to support her over Walker.

Republican Party executive director Joe Fadness alleges in the complaint that the ad violates Wisconsin state law prohibiting corporations from making donations to candidates.

Fadness says the newspaper ad uses "corporate funds to buttress the stated position of the Burke for Wisconsin Campaign Committee," and uses language parroting Burke's talking points.

Fadness asked the Government Accountability Board to commence an investigation. The board does not comment on pending complaints.

Burke continued the criticism of Walker's ad on Monday.

"For him to drag a great Wisconsin company through the mud is bad for business — it's all about politics with him," she said in a statement. "If he knew more about business he would understand the global marketplace and how you compete worldwide."