Egyptians are due to vote in a referendum that is expected to confirm sweeping changes to the constitution and could allow President Abdel-Fatah al-Sisi to remain in power until 2030.

The rush to the ballot boxes was triggered when 531 out of 596 members of parliament backed the constitutional amendments on Tuesday. The national electoral commission declared the next day that the public vote would begin on Saturday.

The proposed changes would extend Sisi’s current term by two years and allow him to run for a third in 2024. They would also enshrine the military’s role in politics and increase Sisi’s control over the judiciary, while creating an upper house of parliament, a vice-presidential position and a minimum 25% quota for female MPs.

Even if the speed of the vote was unusual, that a referendum was happening surprised no one, as banners and posters in support of the changes had covered the streets for weeks before the vote in parliament. The adverts said: “Participation is an act of responsibility” and voters should “do the right thing”, while TV channels released music videos that declared people should “go down and participate”. None of the messaging suggested citizens should participate in order to vote no.

An online petition against the changes was repeatedly blocked by the government. Khaled Dawoud, a longtime opposition figure and a member of the Civil Democratic Movement set up to oppose the changes, said: “We see [the changes] as a major setback for the achievements made by the Egyptian people during the 2011 revolution.”

The speed with which the referendum was declared provided little time to get international observers in place. Monitors from the African Union who observed the election last year said they were not scheduled to return for the referendum.

Sisi renewed his mandate in 2018 with 97.8% of the vote. Under his rule, Egypt has incarcerated at least 60,000 political prisoners, and citizens are subject to harsh austerity measures.

Despite few expectations that the vote would be fair, the chance to express even a limited amount of dissent could encourage some to go the polls who have not voted in years, including activists associated with the 2011 uprising that toppled Hosni Mubarak.

“I just think it’s the right thing to do to show that there are still voices who reject this, even knowing that it won’t affect the result,” said one former activist who asked not to be named for his own safety. “It’s an exercise to keep our voices alive. This is the minimum, safest act of resistance possible.”

HA Hellyer, a senior associate fellow at the Royal United Services Institute, a London-based thinktank, said: “Within 60 hours of parliament voting on the constitutional amendments, Egyptians are supposed to vote in a referendum on them, with little to no public discussion that could be possibly sufficient to cover the ramifications. That hardly sends the message that the public’s involvement in this process is highly valued.”