Wisconsin Gov. Scott Walker (R) released an ad on Tuesday in which his female lieutenant governor applauds his support for equal pay for women -- just two years after the governor signed a bill repealing the state's equal pay law.

"Under Scott Walker, workplace discrimination will always be illegal for any reason," Lt. Gov. Rebecca Kleefisch says in the ad. "Mary Burke wants to create more opportunities to sue. We want to create more opportunities for women to succeed."

Walker's campaign released the ad soon after recent polls showed him and Burke, his Democratic challenger, in a dead heat, with Burke leading heavily among women.

Burke has criticized Walker for quietly signing a measure in 2012 that repealed Wisconsin's Equal Pay Enforcement Act. The law gave victims of wage discrimination more avenues through which to plead their cases in court.

Walker never publicly commented on his decision to sign the equal pay repeal and his office never released a public statement about it. But Republican lawmakers who backed the repeal said the equal pay law was generating unnecessary hassles for businesses and false claims of pay discrimination.

“It’s an underreported problem, but a huge number of discrimination claims are baseless," said state Sen. Glenn Grothman (R) shortly after the law was repealed.

But the equal pay law appears to have been effective. Between 2009, when the law was signed, and 2010, Wisconsin women saw a 3 percent spike in median income measured as a percentage of male earnings. In the two years the law was in place, not one pay discrimination lawsuit was filed, and Wisconsin rose from 36th to 24th in the rankings of states with the best ratio of female to male pay.

By contrast, after Walker repealed the legislation in 2012, Wisconsin dropped to 25th in wage gap rankings, according to 2013 data.

One of the Democrats who co-authored the equal pay bill said it clearly had an effect on employers, even without leading to any more lawsuits. “Since the law was put into place, employers actually took notice and were very conscious of the fact that they had to follow this law or they were at risk of a lawsuit," state Rep. Christine Sinicki said in 2012.

EMILY's List, a progressive women's PAC that supports Burke, said Walker's new equal pay ad is a lie.

"When it comes to the issues that matter to women, Walker has nothing to offer but direct-to-camera lies," said Marcy Stech, a spokesperson for the group. "Walker and Kleefisch know that their record is out of step with the women of Wisconsin whose votes they are desperate to capture -- so blurring their record is their only option."

"Voters are too smart to fall for these last-ditch efforts to mask Walker's record of working against economic opportunity for women," she added.

Stephanie Wilson, press secretary for Burke's campaign, said, "Governor Walker's record is clear: he repealed pay equity protections for Wisconsin women. Mary Burke strongly supports equal pay for equal work and will ensure that every Wisconsinite willing to do the hard work gets a fair shot."