Story highlights The conservative group Future45 is planning to air ads attacking Hillary Clinton over her speech transcripts

Clinton's campaign dismissed the ad as another attempt by Republicans to boost Vermont Sen. Bernie Sanders

Charleston, South Carolina (CNN) A conservative super PAC tied to a number of top Republican donors will start airing an ad Saturday that knocks Hillary Clinton for delivering paid speeches to Wall Street and corporate groups and refusing to release the transcripts of those speeches.

The ad, which will air on CNN and MSNBC through Super Tuesday and was made by the group Future45, is the most recent attempt by Republicans to force Clinton to release transcripts of her paid speeches.

"Hillary Clinton gave speeches to the biggest banks on Wall Street after one of the worst financial crises in American history," a narrator says over video of a Clinton look-alike opening a check from Goldman Sachs. "But Hillary won't tell us what she said to those banks. They paid her over 1 million dollars and are contributing millions more to elect her."

The ad concludes, "So before you promise your vote to Hillary, don't you deserve to know what she promised to them?"

Clinton's campaign dismissed the ad Thursday as another attempt by Republicans to boost Vermont Sen. Bernie Sanders, Clinton's Democratic opponent.

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