Alaska Sen. Ted Stevens' corruption trial will move forward Monday, after a federal judge rejected a defense motion calling for a mistrial.

U.S. District Judge Emmet Sullivan ruled late Thursday afternoon against the motion, after hearing heated arguments from attorneys in the case. Defense attorneys had accused the government of withholding evidence that could help them prove the innocence of the 84-year-old GOP stalwart.

The defense, in hastily prepared court papers, accused the government of seeking to sabotage its case by withholding the key piece of evidence — FBI reports favorable to Stevens — until nearly midnight on Wednesday. The FBI investigation has already sent several other Alaska lawmakers to prison, but the dispute threatened the crown jewel of the case.

"Enough is enough," the papers read. "The court should dismiss the indictment. In the alternative, the court should immediately declare a mistrial. ... It is impossible at this point to have a fair trial."

Sullivan seemed stunned by the development, calling it "unbelievable," and threatening to dismiss the government's indictment against Stevens.

In an earlier series of heated exchanges in court, he lashed out at prosecutors, then sent jurors home so he could decide whether the trial, now in its second week, should go forward.

"This is not about prosecution by any means necessary," he said. "It's not about hiding the ball. ... I find it unbelievable that this was just an error."

Lead government prosecutor Brenda Morris nervously described the omission of the FBI reports as "mistake," which the government had now corrected.

"It wasn't done intentionally," she said. "It was human error."

Sullivan later said that while he believed the government had violated his direct orders to provide relevant evidentiary information to the defense, he did not see a violation egregious enough to warrant an immediate end to the court proceedings. But he scolded the prosecution, saying he had "no confidence" in their ability to "discharge its obligations" by providing all necessary evidence to the defense.

This is the second major mistake made by the government this week. The defense called for a mistrial at the beginning of the week when it learned that Robert "Rocky" Williams, the VECO employee who is thought to have acted as one of the foreman on the Girdwood renovation, was sent at government expense back to Alaska at the end of last week without testifying.

Williams had been in Washington, D.C. for two weeks prior, and was being prepped for his appearance on the stand. The government explained that Williams was in failing health, and he had to be sent back to Alaska to be placed in the care of his own physicians. The defense countered that the government sent Williams out of town because the narrative he gave them didn't match the one they wanted to present at trial.

Stevens, 84, is accused of lying on Senate forms about receiving more than $250,000 in home renovations and other gifts from an oil pipeline firm, VECO Corp. The senator acknowledges that he had his old friend, VECO chief Bill Allen, oversaw the project, but says he made it clear he wanted to pay for everything and never knew Allen was footing the bill.

The jury had been expected on Thursday to hear secretly recorded audiotapes of phone conversations between Allen, the prosecution's star witness, and Stevens, the longest-serving Senate Republican.

Prosecutors say the tapes back up testimony earlier this week by Allen that he never billed Stevens for work by VECO employees that helped turn a tiny ski cabin into a two-story home with a garage, sauna, wine cellar and wraparound decks. Allen told the jury he didn't feel right about billing his fishing and drinking buddy.

Defense attorney Brendan Sullivan argued Thursday that prosecutors violated evidence rules by not turning over the heavily redacted FBI reports well before Allen took the witness stand. The reports, he said, showed that Allen believed Stevens was willing to pay for the renovations — a point he would have made in his opening statement if he had known.

"The integrity of this proceeding has been breached," Sullivan said.

One of the documents, dated February 2007, stated, "The source did not invoice STEVENS for the work ... however, the source believes that STEVENS would have paid an invoice if he had received one." Lawyers say the source was Allen.

The defense papers also cited what they claimed was a misleading summary of Allen's statements provided by prosecutors in September. It said, "Allen stated that he believed that defendant would not have paid the actual costs incurred by VECO, even if Allen had sent defendant an invoice, because defendant would not have wanted to pay that high of a bill."

Stevens, a patriarch of Alaska politics for generations, has languished in the courtroom as a Democratic opponent back home mounts a strong challenge to the seat the senator has held for 40 years. On Wednesday night, he ventured to Capitol Hill to vote in favor of the rescue plan for the nation's finance system.

FOX News' Ian McCaleb and The Associated Press contributed to this report.