The Justice Department on Thursday asked lawyers around the country to help some drug prisoners prepare petitions for clemency, a dramatic expansion of President Barack Obama's action last month commuting the sentences of eight people he said were serving unduly harsh drug sentences.

The speech by the second-ranking official at the Justice Department, Deputy Attorney General James Cole, came as the Senate Judiciary Committee voted in favor of substantial changes to drug laws that could reduce the nation's prison population and bring exploding costs under control.

Cole's remarks — in which he urged passage of the drug legislation — were a strong signal that the Obama administration intends to press forward with substantial changes in drug policy — an issue that some Republicans are willing to join in an effort to reduce the massive costs of the nation's prison system.

In an address to the New York State Bar Association, Cole said there are low-level, nonviolent drug offenders who remain in prison, and who would likely have received a substantially lesser sentence if convicted of the same crimes today.

"This is not fair, and it harms our criminal justice system," Cole said. "To help correct this, we need to identify these individuals and get well-prepared petitions into the Department of Justice." The department is trying to identify prisoners in similar circumstances to the eight granted clemency last year so it can recommend them to Obama for clemency, he said.

Of the eight inmates whose sentences Obama commuted in December, all were sentenced under old federal guidelines that treated convictions for crack cocaine offenses more harshly than those involving the powder form of the drug.

The federal Bureau of Prisons will begin advising inmates of the opportunity to apply for sentence commutations, Cole said.

Cole said the government is looking to bar associations around the country to help potential clemency candidates.

He told the lawyers that "you each can play a critical role in this process by providing a qualified petitioner — one who has a clean record in prison, does not present a threat to public safety and who is facing a life or near-life sentence that is excessive under current law — with the opportunity to get a fresh start."

Cole said "organizations like yours can help by recruiting interested and skilled lawyers and training them to assist qualified inmates with these petitions." Cole added that the Justice Department's pardon attorney's office can provide guidance to the defense lawyers regarding the clemency process and the standards for considering petitions. A member of Cole's staff is to serve as the point of contact.

Depending on clemency standards that Cole didn't specify, the action could impact dozens, hundreds or thousands of prisoners.

The legislation that cleared the Senate committee could affect about 8,800 imprisoned crack offenders who were sentenced before the Fair Sentencing Act became law in 2010. That act reduced penalties to lessen the disparity between crack and powder cocaine offenses.

In the past two years, courts applied a retroactive reduction to sentences for crack that resulted in about 60 percent of offenders who asked for reductions getting them, according to a U.S. Sentencing Commission report.

On the legislative front, liberal Democrats joined by tea party Republicans have pushed hard for sentencing changes, particularly for drug offenders who make up about half of the nation's more than 218,000 federal inmates.

The Judiciary Committee voted 13-5 to advance a measure that would cut the length of many nonviolent drug sentences by as much as half. It would also give judges more discretion by expanding a safety valve provision already on the books that allows a limited number of nonviolent drug offenders to avoid mandatory sentences. The new law would give judges the ability to use the safety valve in all cases involving nonviolent drug offenders if certain conditions are met.

"Take a look at where we are today," said Sen. Dick Durbin, D-Ill. "We have 500 percent more inmates than we did 30 years ago. Federal prisons are 40 percent over capacity." Durbin and Sen. Mike Lee, R-Utah, introduced the legislation, which is called the Smarter Sentencing Act.

In his speech, Cole said such legislation "could not only increase our confidence in our criminal justice system but also save our country billions of dollars in prison costs while keeping us safe."