Hundreds of activists in the Democratic Republic of the Congo are risking arrest and torture to educate voters about their rights in the final days before the country’s long-awaited presidential election.

Members of Lutte Pour Le Changement, (Lucha, or Struggle for Change) have been running a door-to-door campaign to ensure voters go early to the polls, exercise their constitutionally guaranteed rights and “don’t get misled by false and demagogic promises”.

“We are very optimistic. We know the price we may have to pay is less than the prize we might win: a better future for our country,” said Jean-Paul Mualaba Biaya, 27, an unemployed economics graduate and Lucha activist in the southern city of Mbuji Mayi.

The poll was due to be held last Sunday but was delayed by a week. Electoral officials said the postponement was due to a spate of ethnic violence, an ongoing Ebola outbreak and problems caused by a recent fire that destroyed crucial material at an election commission warehouse in the capital, Kinshasa.

The delay to the election, already postponed repeatedly since 2016, angered supporters of the DRC’s fractured opposition. The outgoing president, Joseph Kabila, refused to leave office at the end of his second term in 2016 and only reluctantly agreed not to stand this time. The country’s constitution limits presidents to two consecutive terms.

Emmanuel Ramazani Shadary, a former interior minister and Kabila loyalist, is standing for the ruling coalition instead. Kabila has been in power since 2001, and the election would be the DRC’s first democratic transition of power since independence from Belgium in 1960.

Observers hope the poll will bring a measure of security to the country. It is also likely to raise tensions and could prompt significant protests. Many fear further delay, which might tip the country into chaos.

Lucha was founded in the eastern city of Goma in the aftermath of contested elections in 2011. Its members have faced systematic repression. Hundreds have been arrested in recent years, often during protests against the government. Many members are jailed for long periods in appalling conditions on spurious charges. Others lose jobs or are otherwise penalised for their activism. Luc Nkulula, a prominent leader of Lucha, was killed in a mysterious fire at his home in Goma this year.

“We are under surveillance all the time. They arrested me and tortured me. I was beaten all over. I was asphyxiated. It was very tough, terrible,” said Mualaba, who was held for six weeks in 2016 before being released after a court hearing.

A 27-year-old management student from Mbuji Mayi said friends had been abducted, harassed and detained. “Conditions in prison were terrible. There were 50 men in a room that was four metres long and four metres wide. There was no clean water, nothing to eat, no medicines. Every challenge just makes us stronger,” he told the Guardian.

However, Lucha activists in Kinshasa said they had not been targeted “as badly as before” during the campaign for the current election. “It’s been OK, relatively speaking. I think they are focusing on other threats,” one senior activist said.

Analysts say Lucha makes a useful contribution to efforts to strengthen democratic institutions in the DRC but is not a significant political actor.

The main weakness of those opposing Shadary is disunity. After two political heavyweights were banned from contesting the election on legal technicalities, the remaining opposition candidates failed to unite on a common platform.

There are also widespread fears that new voting machines are impractical in a huge country with limited transport infrastructure and electricity, and could open the way to widespread fraud. Roughly 100,000 machines are to be distributed across the country, which is the size of western Europe.

Western diplomats have urged restraint following the delay but privately admit further postponements could cause “serious problems”.