Republican gubernatorial candidate Kurt Zellers renewed his pledge Wednesday that he will never increase taxes if elected.

"I think Minnesotans need to know going in before they elect a governor that they won't raise taxes," the former Minnseota House Speaker told reporters. "I made that commitment in the past, whether on paper or in person, but I think now more than ever after the confusion we've seen in the last two years, that it's critically important that voters know going in."

Zellers' pledge to Americans for Tax Reform coincides with the launch of his first broadcast advertisement with weeks go to until the Aug. 12 primary, where he faces off with three other GOP contenders for the nomination to take on Gov. Mark Dayton. In the advertisement, Zellers says he took on Dayton and won, preventing him from raising taxes in a showdown between Dayton and the GOP-controlled Legislature that led to the 2011 government shutdown.

"I've never raised taxes, and I'll never do it as your governor either," Zellers said in the ad, with a Wright County farm as a backdrop. "I'm the only candidate in the race who has the guts to put it in writing."

Zellers said the no-tax-increase pledge ranges from individuals to business owners, even cigarettes.

Zellers said that of his three fellow GOP contenders—Former GOP House Minority Leader Marty Seifert, Hennepin County Commissioner Jeff Johnson and businessman Scott Honour— "to date, there's been no one" who has taken a similar pledge.

Though his stance on refusing to raise taxes hasn't changed, Zellers said it's important to take the pledge to reiterate where he stands.

"If you are going to run against three other very well-qualified candidates but also a governor, you have to let the voters know," Zellers said. "I would rather err on the side of making sure they know than have someone think 'Well, all those politicians said they were gonna tax rich people and now I'm paying a dollar more on a pack of smokes.'"

If elected, Zellers said any proposed tax increase sent to his desk from the Legislature would be vetoed.

Zellers wouldn't say if he intends to run more television ads before the primary. The current ad airs on cable statewide in the Rochester, Fargo-Moorhead and Minneapolis and St. Paul markets.