Bill Clinton launched a sustained attack on Bernie Sanders at a New Hampshire campaign rally Sunday, tearing into the senator's rhetoric against Hillary Clinton and picking apart his spending plans.

The former president appeared angry as he poured scorn on his wife's opponent, portraying the Sanders campaign as dishonest and his healthcare proposals as unrealistic.

Bill Clinton said Sanders' message was "hermetically-sealed" from reality and ridiculed its implication that "anybody that doesn't agree... is a tool of the establishment.'"

 Bill Clinton Attacks Bernie Sanders' Healthcare Record 0:50

The remarks late Sunday in New Hampshire marked a significant escalation in the language Bill Clinton has used on the campaign trail and came as polls suggest Sanders could be headed for a clear victory in the state's upcoming primary.

Bill Clinton appeared visibly frustrated at criticism over his wife's ties to Wall Street as he spoke to a crowd of about 300 at a middle school in Milford, New Hampshire.

 Bill Clinton Blasts Bernie Sanders' View on Economy, Wall Street 0:45

"She's getting it from the right, she's getting it from the left," he said. "If she were really so weak on Wall Street, would there really be two hedge fund managers setting up two super PACs and spending millions of dollars to attack her? No, they'd be attacking her opponent.

"But they're not, they're attacking her. Because they know that she's got a stronger plan and they know that when she says she's going to do something, she's going to do it," Bill Clinton told the crowd.