A Tunisian court on Monday sentenced four potential presidential election candidates to eight months in prison and banned them from running for office on a charge of vote buying, politicians and a lawyer told Reuters, a move they said was aimed at excluding serious competitors of President Kais Saied.

The ruling reinforces the fears of opposition parties, candidates and human rights groups who have accused authorities of using arbitrary restrictions and intimidation in order to ensure the reelection of Saied in a vote set for October 6.

The decision was issued against prominent politician Abdel Latif Mekki, activist Nizar Chaari, Judge Mourad Massoudi and another candidate, Adel Dou, said lawyer Mokthar Jmai.

Ahmed Nafatti, the manager of Mekki's campaign, said they still planned to submit his candidacy papers on Tuesday.

"The decision is unfair and unjust, and aims to exclude a serious player from the race," Nafatti said.

"It is a shocking rule, it aims to keep us away from running for the race after a series of restrictions," Chaari told Reuters.

Another court late on Monday sentenced Abir Moussi, also a prominent opponent of Saied, to two years in prison, on a charge of insulting the election commission, local Mosaique radio reported.

Last month, a court sentenced Lotfi Mraihi, a potential presidential election candidate and fierce critic of Saied, to eight months in prison on a charge of vote buying. It also banned him from running in presidential elections.

Elected in 2019, Saied dissolved parliament in 2021 and began ruling by decree in a move the opposition described as a coup. He has said he will not hand over power to what he calls "non-patriots."

Opposition parties, many of whose leaders are in prison, have accused Saied's government of exerting pressure on the judiciary to crack down on his rivals in the 2024 elections and pave the way for him to win a second term.

Saied has denied placing any restrictions on rivals.

"There are no restrictions on potential candidates for the presidential elections... this is nonsense and lies," Saied told reporters on Monday after submitting his official candidacy file.

Earlier on Monday, at least four other prominent potential candidates said the election commission had imposed a new restriction by demanding they submit their police record in order to register, but that the interior ministry had refused to provide those records.

They accused authorities of seeking to return Tunisia to the years of dictatorship and farce elections that were the norm before the Tunisian revolution in 2011. The interior ministry was not immediately available for comment.