MANCHESTER, N.H. — A dispute over a data breach has dominated the news cycle in the days leading up to tonight's Democratic presidential debate here, and the fight seems likely to continue on the stage at Saint Anselm College.

At least one staffer working for Sen. Bernie Sanders, I-Vt., has been punished for improperly accessing information from Hillary Clinton's campaign following a technical foul-up by the Democratic party's data vendor that made each campaign's data potentially accessible to its opponent. But both campaigns believe they have been wronged by the way the tech problem — and its aftermath — were handled.

Clinton's team has accused Sanders' operation of "theft" and suggested its conduct was potentially criminal. Sanders' campaign has responded by accusing the Democratic National Committee of unfairly helping Clinton, who is currently the overwhelming frontrunner in the party's primary. According to Sanders' team, they needed to take legal action to prevent the DNC from overreacting to the data breach. A high-ranking aide also said the Sanders campaign has been upset about the debate process for some time.

In a conversation with Yahoo News on Saturday, top Sanders spokesman Michael Briggs said the campaign objects to the way the DNC has handled the primary debates and the data dispute. He also expressed frustration that the data breach was turned into what he described as a "gigantic press issue."

The battle over the breach began late Thursday night when news broke in reports published by the Washington Post and Buzzfeed that Sanders' staffers accessed data from Clinton's campaign. The intrusion was reportedly the result of issues with software that a third-party contractor, NGP VAN, provided to the DNC, which maintains a shared file of voter information for all of the party's top presidential campaigns.

Democratic data breach fight set to spill onto N.H. debate stage

Presidential candidates Hillary Clinton and Bernie Sanders. (Photo: Lane Hickenbottom/Brian Snyder/REUTERS)

As a result of the incident, the DNC temporarily cut the Sanders campaign off from accessing the voter file. The Sanders campaign responded by filing an injunction in federal court Friday afternoon and suggesting the DNC was attempting to throw its weight behind Clinton, instead of acting as a neutral party. In a message to supporters sent Friday, Sanders campaign manager Jeff Weaver said "the Democratic Party Establishment" was attempting to have "a coronation" rather than "a competitive campaign." In the message, published on Facebook by Sanders supporter Jonathan Tasini, Weaver pointed to the way the DNC has scheduled the party's debates as proof of his claims.

"The reality is that the huge turnouts that we've had at our meetings, our strong fundraising, our volunteer base, and quick rise in the polls have caused the Democratic National Committee to place its thumb on the scales in support of Hillary Clinton's campaign. You see that fact evidenced in their decision to bury the Democratic debates on weekends during nationally televised football games. It's more or less an open secret," Weaver wrote.

The DNC scheduled tonight's debate unusually close to the Christmas holiday and also made the unorthodox decision to hold multiple primary debates on Saturday nights, when television viewership is generally lower. These moves are widely believed to benefit Clinton over her two lesser known rivals, Sanders and former Maryland Gov. Martin O'Malley, who is polling a distant third place, because of their greater need to introduce themselves to voters.

Hours after the Sanders campaign filed suit, it reached an agreement with the DNC to submit to an independent audit to determine the extent of the data breach. As a result of this deal, Sanders' team had its access to the DNC voter file restored late Friday night.

In his conversation with Yahoo News, Briggs, the top Sanders aide, said he was satisfied with the terms of the agreement. However, he took issue with the way both the Clinton campaign and the DNC handled the issue.

"It would have been nice if we wouldn't have had to have gone to a federal judge to get the DNC to do what it should have been doing all along," Briggs said.  

Briggs also suggested Sanders' team was unhappy with the fact the incident was made public. And he noted the Sanders campaign waited over twelve hours to take the issue to court in spite of its objections to the party's handling of the matter.

"Even after somebody made this into a gigantic press issue, which it needn't have been, we waited another day before going to court," Briggs said. "Finally, a few hours after going to court, people came to their senses."

The full extent of the incident became clear after the Clinton campaign showed logs to reporters indicating multiple Sanders staffers accessed data from Clinton's team on over 20 occasions. Clinton's campaign also revealed that the Sanders staffers copied the information, which included estimated turnout figures and information about voters Clinton's operation is targeting in early primary states. Briggs said the Sanders campaign was not provided information about the extent of the breach prior to the Clinton team making the logs public.

"We saw a lot of them on Twitter," Briggs said of the logs, adding, "We're still reviewing ... what our guys did."

Briggs also described the Sanders campaign's concerns about debate scheduling as long-simmering.

"The senator was not consulted, our campaign was not consulted, on the scheduling of the debates. ... They were scheduled shortly after he filed the paperwork with the Federal Election Commission. Not long after that, the senator wrote a letter to the DNC chairman saying that he thought there should be more ... debates and even that it would be interesting to have debates with the Democratic and Republican candidates," Briggs said of Sanders. "That's his position, that the debates are one way of generating excitement about the process and engaging people ... and that scheduling these debates on the Saturday night before Christmas is probably not the most opportune time to do that. But that's what they decided to do and we're playing the hand that was dealt us."

Briggs also suggested the Sanders campaign objected to the timing of the last debate, which was held on a Saturday in Iowa last month on the night of a major college football game in that key primary state.

"Was it a coincidence that the Iowa debate was held on the same Saturday night that Iowa and Iowa State were playing football?" Briggs asked.  

Briggs said Sanders personally saw evidence the football game distracted from that debate.

"I was with Bernie at breakfast at a Perkins in Des Moines the next morning and a couple of people came up to him at the table and said he'd done a good job," Briggs recounted. "He asked them if they watched it, and one of them said, 'I Tivo'd it.' And the other said that they were watching the football game, too, and just had read about it."

Though Briggs suggested the Sanders campaign has long had concerns about the DNC's debate scheduling, it has been less focused on raising the issue than its opponent, O'Malley, who has described the process as "rigged" and petitioned for more debates. Briggs implied O'Malley's poll numbers are the reason he's taken such an aggressive approach. O'Malley is far behind Sanders and Clinton.

"Clearly Gov. O'Malley has been interested in more debates, for obvious reasons," Briggs said.

Briggs said it was too early to tell whether the explosive accusations the Sanders campaign has made following the data breach scandal are a sign he and his colleagues on Sanders' team will change their tone going forward.

"I don't know the answer to whether there will be a reversal," said Briggs when asked about their approach.

Still, it seems clear the issue could come up at tonight's debate. The Sanders campaign hasn't been alone in loudly airing grievances. On Friday night, Clinton's team held a conference call where it blasted the Sanders campaign for the breach. Clinton spokesperson Brian Fallon accused the Sanders campaign of attempting to minimize the situation and suggested on cable TV that it needed to "admit wrongdoing."

Briggs said the Sanders campaign was still "reviewing" what happened and hinted it might punish additional staffers along with the one who was fired.

"I expect that there might be some further actions," Briggs said.

In light of this, Briggs suggested it was unfair of Fallon to accuse the campaign of failing to come clean.

"We fired somebody. That's admitting wrongdoing," Briggs said, adding, "Brian can go to the back of the class and throw spitballs at somebody else."

Fallon did not immediately respond to a request for comment on this story.