Togo lawmakers on Friday gave final approval to a constitutional reform that switches to a parliamentary system that triggered criticism from opposition parties who say it allows President Faure Gnassingbe to keep a grip on power.

The approval came days before April 29 legislative elections in Togo, where the opposition dismissed the reform as a "constitutional coup" for creating a new prime minister-style post they say will allow the Togolese leader to avoid term limits to stay in office.

Togo's parliament had already adopted the new constitution on March 25, but Gnassingbe asked lawmakers to vote again after the reform sparked political tensions.

The second reading was passed with 87 lawmakers present all agreeing to the new system.

Opposition parties see the amendment as a way to extend the mandate of Gnassingbe, who has been in power since 2005 after succeeding his father who himself ruled the small West African state for nearly four decades.

The current constitution would only allow the Togolese leader to run for one last term in 2025.

Under the new constitution, Togo adopts a parliamentary system, leaving lawmakers to elect the president which would become a largely ceremonial role with a four-year term.

Under the amendment, power would shift to the new post of president of the council of ministers, a kind of prime minister, who would also be chosen by parliament, which is dominated by Gnassingbe's ruling UNIR party.

That post would have a mandate of four years, though it is unclear whether the president of the council can be re-elected to another term.

Opposition parties fear Gnassingbe will be appointed by loyalists to the new position, allowing him to stay in power indefinitely. He has not commented on the new post.

"Time has shown us that the major concern of his regime is to preserve power by any means," Nathaniel Olympio, president of the opposition party Parti des Togolais, told AFP before the vote.

"The function of President of the Council gives someone the latitude to exercise power in an unlimited manner, so logically we believe that this is the position that he will hold for himself."

- Opposition ends boycott -

The Togolese head of state had already amended the constitution in 2019 allowing him to reset the time period and run for two new additional mandates.

Togo's new deputies will be elected in a ballot on April 29, after the election date was postponed several times by the government.

Unlike the last legislative elections in 2018 which they boycotted, opposition parties have decided to try to mobilise massively this year.

Opposition parties had planned two days of protests on April 12 and 13 against the reform, but the authorities banned the demonstrations.

A mission from the regional bloc the Economic Community of West African States (ECOWAS) has been on an observation mission in the capital Lome since Monday.