An Egyptian man outside a polling station holds a banner reading: "Vote with us... now... now."
CNN  — 

Egypt has voted to give President Abdel Fattah el-Sisi sweeping powers that could keep him in office until 2030.

The National Elections Authority announced on Tuesday that Egyptians had voted to pass a number of major changes to the country’s constitution in a three-day referendum, with 88.83% voting in favor of tightening its strongman leader’s grip on power.

“The referendum came out in the best possible way, worthy of Egypt’s future and its aspirations for tomorrow,” Lashin Ibrahim, the head of the National Election Authority, said in the press conference. “We have moved from the stage of rebuilding the state and democratization to the stage of consolidating democracy.”

Fourteen amendments to Egypt’s 2014 constitution were up for a vote, as well as two new articles. Egypt’s parliament voted last week in favor of the changes.

One amendment would extend a presidential term from four to six years. It would also add two more years to Sisi’s current term and allow him to seek re-election for another six-year term in 2024.

Another measure would expand Sisi’s power over the legislative branch by creating an upper house known as a senate. The president would be able to handpick a third of the members.

An Egyptian soldier and a policeman stand guard at a polling station in Cairo.

Meanwhile, the lower house would be reduced from 596 to 450, with at least 25% of seats reserved for women.

The revised charter would also give the president new authority to appoint members of the judiciary.

But opposition activists have accused Sisi’s government of pressuring people to vote in its favor. One of a small number of opposition members of parliament, Ahmed al-Tantawi, said voters faced intimidation and “vote buying,” Reuters news agency reported.

Activists have also posted photos to social media that showed white cardboard boxes packed with groceries being handed out to people after they voted.

But the country’s electoral commission has denied any wrongdoing and said it had not received formal complaints about irregularities.

Since the constitutional amendments were proposed by pro-Sisi MPs, Egyptian media outlets controlled by Egypt’s security services urged people to vote.

“Sisi is doing good job. Why should we let him go? There is no alternative for him,” said Sayyed Ali Ahmed, 59, a minimarket owner.

A woman casts her ballot in Cairo.

Supporters of the changes said they would bolster Egypt’s economy, which is struggling to recover from the political turmoil of recent years and strengthen security.

Opponents see a further step toward authoritarianism.

“These amendments aim to expand military trials for civilians, undermine the independence of the judiciary, and strengthen impunity for human rights violations by members of the security forces, furthering the climate of repression that already exists in the country,” Amnesty International’s deputy director for the Middle East and North Africa, Magdalena Mughrabi, said last week in a statement.

Sisi, a former army general, became president in 2014 after a coup the previous year. He was re-elected in 2018 with 97% of the vote.

As president, Sisi has cracked down on dissent, with tens of thousands of political prisoners believed to be held in Egypt’s jails.

Human rights groups have accused the regime of widespread and systematic torture of political prisoners, silencing dissidents and using death sentences to “settle scores.”

Sisi’s government has denied the allegations.

CNN’s Ruba Alhenawi, Magdy Samaan and Chandrika Narayan contributed to this report.