Counting was underway in Tajikistan Sunday in a presidential election expected to pave the way for incumbent Emomali Rakhmon to become the longest-ruling strongman in the former Soviet region.

Few are anticipating any hiccups for Rakhmon as he closes in on three decades in power and looks to overtake Kazakhstan's recently retired Nursultan Nazarbayev in the Central Asian longevity stakes.

The Central Electoral Commission said the vote had passed the turnout threshold required for validation, with more than 70 percent of the nearly five million strong electorate casting votes.

Statements of turnouts are a feature of elections in this part of the world however, and are impossible to verify.

Authoritarian Rakhmon faces four other candidates, all viewed as token opponents, in his bid for a fresh seven-year term. Results are expected Monday.

Voters in the capital Dushanbe interviewed by AFP overwhelmingly said they would vote for Rakhmon -- and struggled to name the other candidates.

Zarina Mamadnazarova, a 25-year-old woman who is currently unemployed, said she would vote for Rakhmon "because he is the best president, our national leader".

Tajikistan is voting for the second time this year after parliamentary elections in March
Tajikistan is voting for the second time this year after parliamentary elections in March AFP / Nozim Kalandarov

Another woman, 39, who preferred not to give her name, said Rakhmon had her vote "because the other candidates are not as strong".

While disputed ballots in neighbouring Kyrgyzstan and fellow former Soviet republic Belarus have triggered massive upheaval, similar developments appear unlikely in Tajikistan.

Rakhmon is portrayed by state media as bringing stability to the country following a civil war during the 1990s that pitted government forces against a diverse opposition including Islamist fighters.

Constitutional changes passed in 2016 allowed the "Founder Of Peace and National Unity, Leader of the Nation", as Rakhmon is officially known, to run for office an unlimited number of times.

Rights groups have flagged an intensifying crackdown on opposition, media and civil society since the changes took effect.

Safar Mallayev, 66, was voting for Rakhmon because of his "enormous experience".

Tajik President Emomali Rakhmon is expected to become the longest-ruling strongman in the former Soviet region
Tajik President Emomali Rakhmon is expected to become the longest-ruling strongman in the former Soviet region Press Service of the President of the Republic of Tajikistan / Handout

"Peace is the main thing. If we have peace it means everything will be alright," Mallayev said.

Few would have guessed that former collective farm boss Rakhmon would stay the course when he was elevated in 1992 to the chairmanship of the national assembly -- a position equivalent to head of state -- as fighting between pro-government forces and the United Tajik Opposition raged.

He was elected president in 1994 after the position was re-established, and re-elected in 1999, 2006 and 2013.

None of the votes were endorsed by Western electoral observers.

The candidates he faces exist "to give a veneer of campaign to what is otherwise a non-event," said John Heathershaw, professor of international relations at the University of Exeter in the United Kingdom.

Heathershaw cited the example of Abduhalim Ghafforov, now challenging Rakhmon for a third time.

"In 2006, he gained just over two percent, in 2013, just over one percent, so if he continues on that trajectory he will get very few votes this time," said Heathershaw.

A party that many view as the only real opposition force in the country -- the Social Democratic Party of Tajikistan -- announced that it would boycott the vote not long after a date for the ballot was set.

"We see that all power structures, all levers (of government) work for the benefit of one person," the party's deputy chairman Shokirjon Hakimov told AFP.

Hakimov added that politics in the country under Rakhmon's rule has been defined by "nepotism, regionalism and corruption".

This time round, some observers had expected Rakhmon, 68, to copy 80-year-old Nazarbayev's decision to step down from the top job and install a loyalist in his place.

In Tajikistan, any future succession is likely to be hereditary, analysts believe.

Earlier this year, Rakhmon's son Rustam Emomali was elected chairman of parliament's upper house, which positions him constitutionally as second-in-line to the presidency.