CAIRO, Egypt — Egyptian President Mohamed Morsi attempted to bolster his revolutionary credentials this week by granting a blanket amnesty to prisoners and defendants charged with crimes related to the January 2011 uprising and its aftermath.

The reprieve, which could take months to implement but was welcomed by rights groups, goes a long way toward fulfilling one of the Egyptian uprising’s key demands: the release of all political prisoners.

“This was one of the main demands of the revolution and one of the most important,” said Ayman Abdel Ghani, a member of the supreme committee of the Muslim Brotherhood’s Freedom and Justice Party, of which Morsi was a longtime member. “Those who were unjustly imprisoned can now be set free.”

But even as Morsi moved to uphold one of the revolution’s primary goals, he came under fire for what critics say is the leader’s political opportunism and selective sense of justice.

More from GlobalPost: Tahrir Square gets a makeover

On Sunday, Morsi marked his first 100 days in office — but with little progress made on some of Egypt’s most crucial issues.

“It's just an attempt to distract people from the failure of the 100 days project,” said Wael Eskander, an Egyptian activist. “He could have released the detainees ages ago — it’s just a publicity stunt. There’s so many other revolutionary things he could have done, but he didn’t.”

Morsi’s decree pardons all those arrested, charged or convicted of felonies and misdemeanors committed “in support of the revolution and its goals” from the start of the uprising on Jan. 25, 2011 until his inauguration as president on Jun. 30, 2012.

The amnesty does not include political prisoners charged with murder and non-political prisoners tried in either civilian or military courts. Rights groups say between 500 and 1,000 detainees could benefit from the reprieve, and both public and military prosecutors are now tasked with drawing up lists of those who qualify for release.

If implemented, it would mark a milestone in Egypt’s hard-fought revolution — a now 21-month-long effort that has stood up against outright military rule, lack of police reform and increasing repression.

More from GlobalPost: Anti-US protests, was it all politics?

According to the civil society group called No Military Trials for Civilians, military courts tried more than 12,000 civilians in the period following the resignation of former President Hosni Mubarak.

Most were detained during demonstrations against the then-ruling military generals, including in clashes with riot police at the interior ministry in November 2011 and February 2012, and a massive protest outside the ministry of defense in Cairo in May, when more than 300 protesters were rounded up by military police.

Most of those detained at the defense ministry have been released, but some are still caught up in Egypt’s complicated and opaque judicial system.

Many were charged with damaging property and disturbing public order. Some activists were detained on trumped-up charges of drug or weapons possession, rights groups say.

Revolutionary activists here worry that Morsi will replicate the system of oppression that marked the rule of Mubarak and his army successors, where Egypt’s infamous “emergency law” gave the regime carte blanche to arrest and torture at will.

So far, Morsi’s brief but highly-scrutinized record on matters of justice inspires few in the activist community who point to at least two cases where defendants, including one newspaper editor, are being charged with “insulting the president.”

More from GlobalPost: Is China buying Egypt from the US?

The Morsi-appointed justice minister, Ahmed Mekki, said the president is considering a revamped emergency law.

But his Brotherhood peers say these pardons should prove to Morsi skeptics that he will lead in the spirit of the revolution.

It would be “impossible” for Morsi to revive emergency laws, because “the Egyptian people would never accept this,” Ghani said.

“There are thugs and criminals that need to be arrested, but the problem is the innocent people were imprisoned among them,” he said. “Society should always accept giving freedom to those imprisoned unjustly — and I think because of that there is support for this pardon.”

Still, some legal experts say the decree’s vague wording on crimes committed “in support of the revolution” will likely bog down prosecutors and may complicate the pardon process.

“How do you define an act that was undertaken for the cause of the revolution but was also an act against the state?” said Hafez Abu Saeda, a lawyer and president of the Egyptian Organization for Human Rights.

“If someone attacked a police station during the revolution,” he said, “is this a revolutionary or criminal act?”

Heba Habib contributed reporting for this story.