Tunis, Tunisia -- President Kais Saied was poised Monday to win Tunisia's election by a huge margin, though low voter turnout reflected widespread discontent in the cradle of the Arab Spring pro-democracy uprisings.

Three years after Saied staged a sweeping power grab, rights groups fear his re-election will entrench his grip on power in the only democracy to emerge from the 2011 protests.

Exit polls showed Saied, 66, expected to rout his challengers with 89 percent of the vote.

His imprisoned rival Ayachi Zammel trailed far behind with just 6.9 percent, while Zouhair Maghzaoui was expected to win just 3.9 percent, according to exit polls broadcast on national television on Sunday.

But with turnout at only 27.7 percent of the nearly 10 million eligible voters, according to the ISIE electoral authority, critics said the low participation reflected a widespread sense of disillusionment with the vote.

After the ouster of longtime dictator Zine El Abidine Ben Ali in 2011, Tunisia prided itself on being the birthplace of the regional revolts against authoritarianism that became known as the Arab Spring.

But the country's path changed dramatically after Saied's election in 2019. Two years later, he dissolved parliament, and after that, he rewrote the constitution.

Turnout was down dramatically on the 58 percent when Saied was first elected five years ago and is the lowest the country has recorded in a presidential vote since it ousted Ben Ali.

"I didn't vote yesterday, simply because I no longer have confidence and I am desperate," said Houcine, 63, giving only one name for fear of retribution.

"The vote's legitimacy is undoubtedly tainted with candidates who could have overshadowed (Saied) being systematically sidelined," said Hatem Nafti, a political commentator and author of a forthcoming book on the president's authoritarian rule.

Nafti said Saied "retains his electoral base but has lost nearly a million votes" compared to 2019, when he won in a landslide with 73 percent of the vote.

The poll was widely shunned by young people, with only six percent of voters aged 18 to 35, said ISIE.

But for supporters of Saied, the exit polls prompted celebration on Sunday night, with hundreds taking to the streets of Tunis.

"I voted yesterday, and the results are excellent, everything is going very well, the atmosphere is great," said Mounir, 65.

"What we need now is a drop in prices. We want better education, health and above all safety."

Saied has been widely expected to win since he barred 14 candidates from joining the race, allowing only two challengers, Zammel and Maghzaoui, to stand against him.

Zammel, a little-known liberal businessman, has been behind bars since his bid was approved by the ISIE in September. He faces more than 14 years in prison for forging endorsements.

Maghzaoui, a supporter of Saied's power grab, is largely seen as a non-threat to the incumbent.

Overall, rights groups have condemned a democratic backsliding in recent years.

According to New York-based Human Rights Watch, more than "170 people are detained in Tunisia on political grounds or for exercising their fundamental rights".

Other jailed figures include Rached Ghannouchi, head of the Islamist-inspired opposition party Ennahdha, which dominated political life after the revolution.

Also detained is Abir Moussi, head of the Free Destourian Party, which critics accuse of wanting to bring back the regime that was ousted in 2011.

Ahead of the vote, Saied called on Tunisians to "vote massively" to usher in what he called an era of "reconstruction".

He cited "a long war against conspiratorial forces linked to foreign circles", accusing them of "infiltrating many public services and disrupting hundreds of projects" under his tenure.

Ben Ali and other Arab leaders often cited foreign conspiracies to justify their crackdowns on dissent.

The International Crisis Group think tank has said that while Saied "enjoys significant support among the working classes, he has been criticised for failing to resolve the country's deep economic crisis".

Celebrating the exit polls at his campaign's office in the capital, he warned of "foreign interference" and pledged to "build our country and we will rid it of the corrupt and conspirators".

Analyst Nafti said Saied will use re-election as a carte blanche for further crackdowns and to "justify more repression".

"He has promised to get rid of traitors and enemies of Tunisia," he said. "He will harden his rule."