把柄 (bǎ bǐng): handle; (fig.) information that can be used against sb

During the negotiation, the other side accidentally revealed a financial loophole in their company. We held firmly onto this leverage and ultimately forced them to make concessions.

Evidence of him taking bribes fell into the hands of journalists. This leverage was enough to cost him his official position and even land him in prison.

She had always known about the mistake her husband made when he was young, but she never used this leverage to threaten him, because she believed marriage should be built on trust.

Colleagues should cooperate sincerely and not go around collecting leverage on others; otherwise, once people find out, you yourself will lose everyone's trust.

As the election entered its final stage, the opponent suddenly released an anonymous report, trying to use this leverage to smear him, but the voters didn't seem to buy it.