The Constitutional Court is expected to rule by August on the legality of conscientious objection to military service.
In 2004 and 2011, the court ruled against conscientious objectors, making national defense a priority over individual rights.
"There is no room for delay, the Constitutional Court needs to make a decision," The Chosun Ilbo quoted an official from the court as saying on Friday. "There is a high possibility a decision will be made by August."
Korea requires all able-bodied men to serve in the military for roughly 21 months _ the core part of the country's defense. The two Korea's are technically at war, because the Korean War (1950-53) ended in a ceasefire, not a peace treaty.
Since the Korean War, around 20,000 conscientious objectors have refused to serve in the armed forces stating their rights to freedom of thought, conscience or religion.
Any male who violates the Military Service Act without a justifiable reason can be imprisoned for up to three years. Since 2004, the Supreme Court has not acknowledged religious conscientious objection as a justifiable reason.
In 2007, Korea was presented with specific measures to adopt an alternative military program for conscientious objectors with five relevant legislative bills.
But the issue was discarded without being discussed, according to a Constitutional Court official.
The legal circle believed it would be difficult to decide on the sensitive issue any time this year because five out of nine Constitutional Court justices are scheduled to be replaced in September, including its president, Lee Jin-sung.
However, the court is speeding up the process to make a decision before the major reshuffle because there are conflicts in the rulings of local courts nationwide.
On March 8, Incheon District Court sentenced a Jehovah's Witness conscientious objector to 18 months in jail.
On the same day, an Ulsan district court handed down a not guilty ruling.
The first acquittal of a religious conscientious objector came in 2004 and 17 had been found not guilty by 2016. However, last year 45 objectors were acquitted, putting more pressure on higher courts for a final ruling.