Clinton said he was especially disappointed with the ad because as governor of Massachusetts Romney himself had requested changes in the law, Politico reported.
"Governor Romney released an ad today alleging that the Obama administration had weakened the work requirements of the 1996 Welfare Reform Act. That is not true," Clinton said Tuesday night.
In an e-mail Romney spokesman Ryan Williams responded that President Obama had been a vocal opponent of the 1996 law considered one of Clinton's signature achievements.
Former Clinton chief of staff John Podesta held a Chicago news conference to rebut the ad and support Obama, Gaggle reported.
Podesta said that Obama was trying to administer the welfare program under much tougher economic conditions.