Military leader says measure long used as tool of repression will only be used to deal with acts of 'thuggery'

The head of Egypt's military junta has promised to partially lift the country's three-decade-old state of emergency, in a last-ditch effort to bolster public support ahead of what are expected to be widespread anti-government demonstrations on Wednesday.

Field Marshal Mohamed Hussein Tantawi, who became Egypt's de facto leader when the army took power following the toppling of Hosni Mubarak last February, used an address to the nation to announce that the state of emergency – used by both the Mubarak regime and the ruling generals that replaced him to repress dissent and shield security forces from accountability – would be suspended, meeting one of the main demands of the revolution that erupted a year ago on 25 January.

But Tantawi said an exception would be made for acts of "thuggery", an ill-defined category of crime that critics claim can be used to violate the legal rights of any citizen.

In the first sign of potential conflict between the military council and Egypt's newly inaugurated parliament, which opened its doors this week, human rights campaigners called on MPs to face down the unelected generals and insist on a genuine roll-back of repressive laws.

"From our perspective, the state of emergency has not been lifted," Hossam Bahgat, director of the Egyptian Initiative for Personal Rights, told the Guardian. "Tantawi's speech does nothing to deal with the most harmful aspect of the state of emergency, which is allowing the police to retain powers to stop, search and detain anyone they suspect of being a 'thug', without having to obtain a judicial warrant.

"His comments are no different from Mubarak's repeated promise to only apply the state of emergency to terrorism and drug trafficking, a promise that was routinely violated and only led to the creation of a state of exceptionality that put the police above the law," Bahgat added. "We call on the new parliament to reject this decree and insist on nothing less than the full and immediate lifting of the state of emergency and a return to normal civilian law."

Security measures were ramped up at government buildings as Egyptian authorities braced themselves for what is expected to be one of the biggest outbreaks of popular unrest since the fall of Mubarak on Wednesday. In an apparent attempt to dampen the energy of revolutionaries, the Supreme Council of Armed Forces has announced a series of official celebrations including military parades, air shows, a specially commissioned operetta and the distribution of prize coupons to citizens on the streets.

But anti-junta demonstrators have vowed to ignore the planned events and instead hold marches and rallies in several cities demanding an immediate end to military rule. "We are not going down to the streets to celebrate," said Ahmed Emam, a member of the Popular Alliance party, at a press conference last week. "We are going down to continue our revolution. We will not celebrate while the blood of the martyrs hasn't dried yet."

On Tuesday new fortifications continued to be added to downtown Cairo's state television building, which was surrounded by barbed wire and armed soldiers and was expected to be a rallying point for protesters. Some high-end hotels in the city were boarding up their windows in expectation of violent clashes, and several airlines cancelled flights to Egypt on the anniversary. The US embassy has warned its citizens to steer clear of the centre of the capital.

Trouble erupted in the Sinai peninsula after a group of bedouin tribesmen stormed a tourist resort in an effort to reclaim land. It was the latest in a string of clashes between the Egyptian state and local communities whose expectations of social justice have intensified with the revolution and who view the present political instability as an opportunity to redress longstanding grievances.

Egyptian media reports claimed that dozens of armed gunmen took control of Aqua Sun, a Red Sea hotel complex boasting a mile and a quarter of private beaches to the south of Taba, and were demanding a £425,000 ransom in exchange for leaving the site peacefully. No tourists were staying in the resort at the time, and the lives of several Egyptian security guards taken hostage during the incident were not believed to be in danger.

Disputes over land have been common in the Sinai since the central government embarked on a "Red Sea riviera" programme of resort construction along the eastern coast in the 1990s. Customary law was replaced by a new system of land ownership and large swathes of previously bedouin-controlled coastal areas were sold to private investors under the auspices of the state, leading to allegations by some locals that they were being cheated out of their property.

Egyptian officials say it is difficult to mount any police or military response given the constraints imposed upon Egypt as a result of its peace treaty with Israel, which regulates the amount of security personnel the government can deploy to this sensitive border region. The relationship between the two countries became a significant political issue during the Egyptian parliamentary election campaign, but no major party has seriously suggested withdrawing from the 1978 Camp David accord.

"The bedouin are among the many marginalised groups in Egypt pressing for their rights since the revolution began last year," said Elijah Zarwan, a Cairo-based political analyst. "There's long been a security vacuum in the Sinai and now on top of that you have a more generalised security vacuum throughout Egypt. It's no wonder that the bedouins, who are often well armed, feel emboldened to press for their rights more forcefully."

This month residents in the Mediterranean coastal town of Dabaa broke through the security perimeter of a large government-owned site earmarked for a future nuclear power plant and blew up several under-construction buildings, including one that was believed to be the reactor. The Mubarak-era nuclear project has long attracted fierce opposition from the local community, who say they have been deceived on multiple occasions by the authorities and are now intent on reclaiming the land for themselves.

Last week it emerged that some protesters had stolen radioactive material from the site, following clashes between security forces and protesters that left dozens injured. On Monday the government vowed to press ahead with the nuclear plant regardless, warning locals against any more "violations of state-owned property".