Lawmakers could soon be handing the Justice Department new ammunition in its fight against Congressional corruption.

The Senate Judiciary Committee today will mark up a bill that will give federal prosecutors more time and resources to uncover wrongdoing by lawmakers while toughening anti-corruption laws already on the books.

The measure, co-sponsored by Judiciary Chairman Patrick Leahy (D-Vt.) and Sen. John Cornyn (R-Texas), would authorize pumping an additional $100 million into corruption investigations and prosecutions over the next four years.

And it would give federal investigators more time to track down bribery, honest services fraud and extortion by extending the statute of limitations on those crimes from five to six years.

The bill also would clean up ambiguities in the law — opened by recent court decisions — by clarifying what constitutes an illegal gratuity and broadening the definition of an “official act.”

After cheering the passage of a lobbying and ethics overhaul earlier this year, reform advocates on and off Capitol Hill are now turning their attention to issues of enforcement.

Leahy introduced a pared-down version of his bill in early January but failed in an attempt to attach it to the lobbying reform package. He dusted off the measure this summer, and on Aug. 2 — the day the Senate approved the final version of the lobbying bill — reintroduced it with some additions from Cornyn.

“If we are serious about addressing the kinds of egregious misconduct that we have recently witnessed in high-profile public corruption cases, Congress must enact meaningful legislation to give investigators and prosecutors the tools and resources they need to enforce our laws,” Leahy said in a statement at the time.

Cornyn, in a statement, said public corruption is not a GOP or Democratic problem. “It’s a Washington, D.C., problem. And it’s a problem in statehouses and city halls across this country … This bill will strengthen the enforcement of U.S. federal laws aimed at combating betrayals of public dollars and public trust.”

A Justice Department spokesman did not return a call for comment, but a Leahy aide, speaking privately, said the department has indicated its support for the bill.

Judiciary panel aides said they expect the bill to clear the committee today, but whether it gets a floor vote is another story. One raised doubts, pointing to the crowded end-of-year calendar.

Meanwhile, a House companion bill, introduced in April by Rep. Hank Johnson (D-Ga.), has picked up six Democratic co-sponsors but hasn’t budged out of a Judiciary subcommittee. The measure mirrors Leahy’s more basic proposal from January.

With momentum in the Senate, a coalition of watchdog groups on Wednesday circulated a letter to Judiciary members asking them to back the bill.

“This bill gives sufficient resources to investigate and prosecute these cases, and it provides effective laws to allow prosecutions to occur for public corruption crimes,” said Fred Wertheimer, president of Democracy 21, one of the groups seeking support for the proposal. “Those laws have been narrowed in ways that, in the view of reform groups and of this bill, don’t make sense.”

Ethics lawyers — whose Congressional clients could face beefed-up prosecutors if the measure passes — called the bill heavy-handed and unnecessary.

“I’m personally troubled by the ease with which the executive branch can conduct investigations involving members of the legislative branch,” said Bill Canfield, a lawyer with Williams & Jensen and chairman of the Standing Committee on Election Law of the American Bar Association. “To make it even easier is counterintuitive.”

Said Rob Kelner, the top election lawyer at Covington & Burling: “This is just getting to be silly.”

“The public corruption laws that are on the books now are extraordinarily strict and are accompanied by especially severe penalties,” he said. “We don’t have a problem in this country of inadequately stringent public corruption laws. This statute seems directed at problems that don’t exist in the real world.”

One provision in the bill broadens the definition of an official act to counter a ruling handed down earlier this year by the U.S. Court of Appeals for the D.C. Circuit.

In that case, a former D.C. detective took $450 from an undercover FBI informant to pass along restricted information from a law enforcement database. The court ruled the cop could not be convicted of violating the illegal gratuity statute because the action was not a formal part of his job.

Many ethics lawyers watching the case interpreted the decision as a blow to the ongoing investigation into the Jack Abramoff scandal and the probe of Rep. William Jefferson (D-La.), among others, because it appeared to severely limit the kinds of official favors considered legally out of bounds.

The provision developed in response expands official actions to include any conduct within the range of the official duty of a public official.

Another item in the bill would reverse a 1999 Supreme Court decision that restricted the “illegal gratuities” statute. In the United States v. Sun-Diamond Growers, the court held prosecutors needed to be able to prove a “specific connection” between a gratuity and an official act, effectively elevating the standard for prosecutions of that crime to those for bribery, though the penalties are significantly weaker.

Under the bill, prosecutors would not need to prove an airtight link between the gratuity and an official act, as long as they could show it was given “for or because of” the official’s position — and in violation of gift limits under ethics rules.