The lead group pushing the marriage amendment has released a new television advertisement warning that same-sex relationships could be taught in school if marriage is redefined.

"Parents have a right to know that if marriage is redefined in Minnesota, same-sex marriage could be taught in public schools without prior notice, and parents could lose their right to opt their children out of such instruction, just like in Massachusetts," said John Helmberger, chairman of Minnesota for Marriage, the lead group pushing the measure.

The group trying to defeat the measure immediately blasted the ad, calling it inaccurate and misleading.

"It's clear that supporters of this amendment do not wish to debate the issue truly at hand: whether it should be illegal to marry the person you love, and whether we should use our state constitution to limit the freedom to marry," said Richard Carlbom, campaign manager for Minnesotans United for All Families "Instead, supporters of the marriage amendment continue to try to mislead voters about what's at stake with this amendment, with an ad making claims that have already been determined to be misleading."

The ad opens with a narrator saying: "If gay marriage happens here, schools could teach that boys could marry boys."

The ad features David and Tonia Parker, Massachusetts parents, who say they didn't want their young son learning about same-sex relationships in school.

"After Massachusetts redefined marriage, local schools taught it to children in second grade, including the school our son attended," David Parker says in the ad.

Parker goes on to say courts ruled parents couldn't be told when the lessons would occur or pull their son out of class.

"If marriage is redefined in Minnesota, same-sex marriage could be taught in public schools, just as it was in Massachusetts," Tonia Parker says in the ad. "Don't make the same mistake and think gay marriage won't affect you."

In less than two weeks, Minnesotans will be deciding a proposal to add language to the state Constitution defining marriage solely as a union between a man and a woman.

Same-sex marriage is not legal in Minnesota, but supporters say strengthening the existing law is necessary to block judges or future legislators from changing the law.

Amendment opponents argue the measure will enshrine discrimination into the state's founding documents.

Andy Parrish, deputy campaign manager for Minnesota for Marriage, the lead group pushing the amendment, said the ad will be running statewide.