Former presidential candidate Rick Santorum on Monday asserted that a majority of Americans oppose gay marriage.

Santorum appeared on Bryan Fischer's radio program to promote his studio's upcoming movie, One Generation Away: The Erosion of Religious Liberty.

The former senator from Pennsylvania warned that unless social conservatives actively oppose marriage equality “we will lose this war.”

“How many people do you hear right now saying, 'Ugh, we already lost the marriage issue. It's time to move on. We can't win?'” Santorum rhetorically asked.

“And we haven't even lost yet and the majority of Americans still believe in marriage, and yet our side is willing to fold our tent and go away. We have to understand that this is a war. And if we don't engage in this war, we will lose this war,” he added. (The video is embedded on this page. Visit our video library for more videos.)

Nationwide polls which show a majority of Americans support marriage equality date back to 2010. A survey of 4,509 Americans conducted in February by the Public Religion Research Institute found 69 percent of young adults under 33 favor allowing gay couples to marry.