Story highlights Bernie Sanders' campaign manager Jeff Weaver said that Hillary Clinton has been "all over the map" on gun control

Clinton has revived her hits on Sanders for his gun control record as new polling has shown a surprisingly tight race between the two in Iowa

Washington (CNN) Bernie Sanders struck back at Hillary Clinton on Monday after the former secretary of state repeatedly blasted his previous opposition to gun control measures, saying her own position has changed since 2008.

"People will remember that Secretary Clinton has been all over the map on guns, she's been very conservative on guns, she's been very liberal on guns. People will remember the attacks she leveled against then-Sen. Barack Obama, now President Barack Obama, back in 2008 on guns, when she was tacking to the right on this," Sanders campaign manager Jeff Weaver told CNN's Chris Cuomo on "New Day." "So I think her argument would be much more compelling if she had a consistent record on this issue."

Asked for comment, Clinton campaign chairman John Podesta pointed the issue back to Sanders, saying he "still refuses to admit he got it wrong."

"Between Hillary Clinton and Bernie Sanders, only one candidate has a consistent record fighting against the gun lobby to prevent gun violence. Senator Sanders' record shows he is willing to hold most industries accountable for their abuses, but not gun manufacturers and dealers," Podesta said Monday.

Clinton hit Sanders again Sunday, for supporting legislation granting gun manufacturers immunity from legal action in shootings while he was in the House, in 2005.