A plan approved on Friday could make more than 46,000 federal drug offenders eligible for early release from prison.

The U.S. Sentencing Commission unanimously voted to approve the plan, which will amend sentencing guidelines in some drug cases involving non-violent inmates.

This vote follows April's decision to amend sentences in non-violent drug cases. Under the plan, two-year reductions will be possible to about 46,000 inmates convicted of non-violent drug crimes.

The plan is part of an effort to reduce the overcrowded federal prison system, and it looks like the measures could be well on their way to approval.

Unless Congress rejects the measure, these cases will become eligible for judicial review as early as November 1. However, no prisoners would be released until November 2015.

"The amendment received unanimous support from commissioners because it is a measured approach," said Judge Patti Saris, the panel's chairperson.

"It reduces prison costs and populations ... while safeguarding public safety," she continued.

Attorney General Eric Holder described the action as "a milestone in the effort to make more efficient use of our law enforcement resources and to ease the burden of our overcrowded prison system."

Holder has voiced support for the action in recent months as a solution to federal prison overcrowding and stretched budgets. There nearly 215,000 inmates in the federal prison system, and about 25 percent of the Justice Department's budget is allocated for the incarceration of federal prisoners. 

"The department looks forward to implementing this plan to reduce sentences for certain incarcerated individuals," Holder said.

"In the interest of fairness, it makes sense to apply changes to the sentencing guidelines retroactively. At my direction, the Bureau of Prisons will begin notifying federal inmates of the opportunity to apply for a reduction in sentence immediately."