Updated

When longtime Democratic Rep. Pete Stark adds to his highlight reel of acid-tongued insults it hardly raises an eyebrow, considering his decades-long record of putdowns. But his recent accusation of bribery against a primary challenger in California has his opponent crying foul and claiming the charges are a sign of desperation.

The 80-year-old Stark made the accusations during two recent public appearances, saying challenger Eric Swalwell, an Alameda County prosecutor and city councilman, took “hundreds of thousands of dollars in bribes” from the Lin family, prominent East Bay developers.

“If I were a lawyer, I’d call that bribery,” Stark said at an April 10 debate ahead of the June 5 primary. He then made a similar remark during a town hall-style meeting Saturday.

The 31-year-old Swalwell has taken $5,000 from people with reported professional connections to the Lin family, according to his most recent campaign finance report, in addition to $5,000 in contributions from two people with the last name Lin -- though it's unclear whether they're part of the same family. However, no evidence has emerged showing or suggesting that Swalwell has taken a bribe.

Stark also threw a range of epithets at his opponent at recent campaign events, calling him a "pipsqueak," a "junior leaguer," a reportedly a "slimeball," and a "f---ing crook."

More On This...

Swalwell has not responded to the name calling, but he and his campaign have demanded Stark provide proof of the bribery accusation or retract it.

“His behavior is expected, but there’s no reason to start calling each other names,” Swalwell campaign consultant Lisa Tucker told FoxNews.com on Tuesday. “But to make such a serious accusation is outrageous.”

This is not the first time Stark has made over-the-top statements.

He made a House floor speech in 2003 in which he twice accused President George W. Bush of lying. Along the way, he has also made questionable remarks about Democrats, Jews, women and African Americans. The Republican National Committee a couple years ago assembled a listing that included roughly two-dozen such comments dating back roughly 20 years.

In 1990, he called Health and Human Services Secretary Louis W. Sullivan ''a disgrace to his race'' for opposing proposals for federally sponsored national health insurance.

He said Sullivan, who is black, was “being used by the (Bush) administration and does not have the strength of his own convictions.''

The White House castigated what it called Stark's ''bigoted assault'' and demanded the Democratic Party repudiate it. Stark did not apologize, according to the Associated Press.

Exactly how much damage Stark, who is seeking his 21st House term, has done this time remains unclear. There have been no public polls on the race, though Tucker says both campaigns have done internal ones that will not be released.

The Swawell campaign claims Stark’s comments are a sign he’s in desperate political trouble.

“I cannot explain it any other way,” Tucker said.

Though the state’s 15th congressional district was redrawn last year, the nonpartisan Cook Political Report still lists the seat as “solid Democrat.” The race also has a third-party candidate, an independent and the Tea Party-backed candidate Chris Parajea.

Stark has not responded to requests to elaborate on his bribery comments. He also reportedly told Swalwell, “You’re going to jail.”