Egypt’s ruling general announced the partial lifting of a more-than-three-decades-old emergency law on Tuesday, just a day before the first anniversary of the start of Egypt’s revolt.

In an apparent attempt to appease critics of the country’s military leaders, who assumed power after the ouster of President Hosni Mubarak, Field Marshal Mohammed Hussein Tantawi promised that the law would be lifted Wednesday morning, when mass protests are expected to mark the anniversary.

The abolition of the emergency law, which allows the state to detain and hold Egyptians for virtually no reason, was a key demand of revolutionaries last winter, and it has remained a priority. But Tantawi reserved the right to apply the law in cases of “thuggery,” and human rights groups said the announcement would change little.

Also on Tuesday, members of Egypt’s new parliament showed a clear willingness to take on the military rulers, who have been criticized for being too slow to hold senior officials accountable for the killing of more than 800 protesters last winter.

Mohamed Saad Katatny, the speaker of the parliament and a senior member of the political wing of the Muslim Brotherhood, said the body would establish a committee to investigate the deaths, though lawmakers argued into the night over who would serve on the panel.

The ruling generals have made partial concessions to public pressure several times over the past year, including agreeing to a timetable for the transfer of power to an elected president by the end of June and, more recently, pardoning nearly 2,000 jailed Egyptians. But analysts and human rights groups say the concessions are usually too little and too late.

“This is the classic pre-demonstration concession, or in this case an attempt at portraying something as a concession,” said Heba Morayef, an Egypt researcher for Human Rights Watch. Despite the moves, “the military’s whole intention is to give themselves power over the judiciary,” she said.

Human rights groups said the term “thuggery” has been used as a catchall crime since the military assumed power on Feb. 11 and is so broad that people have been arrested and held with no evidence because they were labeled a thug. In addition, more than 12,000 civilians have been picked up and tried in hasty military-court proceedings in the past year.

In Washington, State Department spokeswoman Victoria Nuland called the lifting of the emergency law a “major step,” but added that U.S. officials have asked the Egyptian government to clarify the possibility that the law could still be applied in some cases.

Hossam Bahgat of the Egyptian Initiative for Personal Rights compared Tantawi’s promise to assurances by Mubarak’s government to use the emergency law only in cases of terrorism and drug trafficking. The law still gave police wide powers to stop, search and detain anyone for any reason, Bahgat said.

“ ‘Thuggery’ is just the military’s word for Mubarak’s ‘terrorism,’ ” he said. “It is even more vague and overly broad and is used to give the police broad powers.”

Tantawi spoke just a day after the country’s new, freely elected parliament convened for the first time. During his televised address, he also praised the armed forces for protecting the goals of the revolution.

“We never strayed from the revolution’s goals, that are in agreement with our goals and positions, and the new parliamentary assembly comes as one of the first important steps on the path to democratic transition,” he said.

Over the past year, revolutionaries have grown disillusioned by the military’s rule. They accuse the military council of botching the transitional period by standing in the way of reform and continuing serious violations of human rights, including forced “virginity tests” on women.

On Wednesday, which has been declared a national holiday, young revolutionaries who spearheaded last year’s revolt plan to protest military rule and mourn those killed in the past year. The military rulers, their supporters and the Islamist parties that won more than 70 percent of the seats in the parliament also intend to commemorate the Egyptian revolution.

Special correspondent Ingy Hassieb contributed to this report.