MADISON, Wis. -

The ad wars in the Republican U.S. Senate race continue, with anti-tax group Club for Growth and Mark Neumann launching new spots on Wednesday.

Neumann's latest ad touts him as being "conservative before it was cool." The ad cites his having been removed for a House budget sub-committee in 1995 for being unwilling to go along with Republican leadership on a spending bill.

Club for Growth attack leading candidates Tommy Thompson and Eric Hovde in its new spot, calling Neumann "the choice for conservative change."

The ads come after Thompson ran a new attack ad against Hovde on Tuesday targeting his $500 donation to Democratic Gov. Jim Doyle in 2005.

The primary is Aug. 14. The Republican winner will advance to face Democrat Tammy Baldwin in November.