The mood during Thursday’s Democratic debate got testy on both sides as Hillary Clinton denounced the attacks Bernie Sanders has been making on her relationship with Wall Street as an “artful smear.”

“Senator Sanders says he wants to run a positive campaign. I’ve tried to keep my disagreements over issues, as it should be,” Clinton said. “Time and time again, by insinuation, there is this attack that he is putting forth, which really comes down to, you know, anybody who ever took donations or speaking fees from any interest group has to be bought. I just absolutely reject that, Senator. I really don’t think these kinds of attacks by insinuation are worthy of you.”

Sanders has repeatedly pointed to the super PACs that have been supporting Clinton as proof she won’t be willing to stand up to big business, and has brought up in particular the hundreds of thousands of dollars Clinton was paid for speeches she gave to Wall Street firm Goldman Sachs.

“Enough is enough. If you’ve got something to say, say it directly. You will not find that I ever changed a view or a vote because of any donation that I ever received,” Clinton continued. “I have stood up and I have represented my constituents to the best of my abilities, and I’m very proud of that. I think it’s time to end the artful smear that you and your campaign have been carrying out in recent weeks and let’s talk about the issues that divide us.”