WASHINGTON (CNN) -- The jury in the corruption trial of Sen. Ted Stevens Monday heard the Alaska Republican use an obscenity to describe the Justice Department investigators pursuing him, as prosecutors played audio of government wiretaps as evidence against him.
"I've never been up against a bunch like this one before," Stevens said in a September 2006 call, referring to prosecutors with the Justice Department's Public Integrity Section.
"I'm not getting much sleep. Maybe four hours, thinking about all this s--t coming down," he told Bill Allen, the former energy-company executive who is the government's star witness against Stevens.
He also told Allen he's "trying to figure out why these f---ers are doing this." Listen to audio of the Stevens wiretaps »
The veteran Alaska politician showed no reaction as the recordings were played in court.
Stevens is accused of failing to report as gifts hundreds of thousands of dollars of renovations to his Alaska home arranged by Allen and the energy services firm he headed, Veco Energy.
The senator pleaded not guilty in July and hopes to clear his name before standing for re-election in November.
Stevens is not accused of accepting bribes, which would require the government to prove he undertook specific actions in exchange for specific payment.
After prosecutors played a third recording, the government handed Allen to the defense for cross-examination.
Allen already has pleaded guilty to attempting to corrupt a number of Alaska officials -- not including Stevens -- and is cooperating with the prosecution.
As head of Veco, he used company employees and resources to improve and maintain the Stevens home in Alaska.
Allen testified that Veco staff who had worked on his own house had charged "way too much," leaving him uncertain how much to invoice Stevens for when he had his staff work on the senator's house.
"Here's the problem," Allen testified. "They did really screw up on my house, it was way too much, but I never really saw how much time or the money was spent on Ted's house. I didn't really, I've never seen an invoice. And so I had no idea how much, but I thought it was probably going to be too much."
Allen agreed with defense attorney Brendan Sullivan that he would be embarrassed to bill Stevens for overpriced labor on the house, and said he concealed some of the expense because it was "way too much."
Sullivan also asked Allen: "You never tried to bribe Sen. Ted Stevens, did you?"
Allen replied, "No."
Allen's testimony came after the defense Sunday urged the judge to throw the case out or declare a mistrial, arguing the prosecution had hidden evidence that would be beneficial to Stevens.
The judge is expected to rule Tuesday on the motion, the second time the defense has filed to dismiss the case.
U.S. District Judge Emmet Sullivan has given the prosecution until Monday night to respond to the defense motion and the defense until Tuesday morning to counter the prosecution response.
The motion is the second one filed by defense attorneys asking for a case dismissal or mistrial. Sullivan denied a similar motion last week.
The defense said Allen quashed some bills for the work on the Stevens home without telling the senator. Allen confirmed that argument on the stand last week, saying he had done it "because I like Ted."
The defense repeatedly has accused the government of concealing information that could help Stevens, the longest-serving Republican senator in history.
The judge last week berated the prosecution for withholding information such as an FBI investigator's report that Allen said Stevens would have paid his bills had he known about them. But Sullivan allowed the trial to proceed.
The bulk of the money the lawmaker is accused of trying to hide is related to construction and renovation at the Stevens family chalet in the ski town of Girdwood, Alaska, about 40 miles from Anchorage. His attorneys have said Stevens promptly paid the bills he knew about, but that his benefactor, Allen, concealed additional costs. See why Alaskans say they support Stevens despite the trial »