Senegalese police fired tear gas on Monday to disperse protesters outside parliament as lawmakers debated a constitutional amendment that would expand parliamentary powers and reduce those of the president, a proposal critics say could upset the balance of power in government.

Senegalese civil society groups and political parties say the reform is an attempted power grab by parliament speaker and former Prime Minister Ousmane Sonko.

Dispute over constitutional reform risks deepening political divisions in Senegal, particularly between President Bassirou Diomaye Faye and Sonko.

Sonko's dismissal in May underscored a widening split over reforms and the response to a mounting debt crisis.

Relations between them remained tense after Sonko was elected speaker of parliament.

The push for constitutional reform has been driven by the ruling Pastef party, led by Sonko. Proposed changes include a provision prohibiting a sitting president from serving as leader of a political party. Faye is also a member of Pastef, but no longer holds any official role in the party.

A political coalition supporting the president has called for an immediate withdrawal of the bill and said Faye should be able to fully exercise his powers.

Faye was elected two years ago, backed by Sonko, a charismatic figure with a strong youth following, who was barred from running himself due to a defamation conviction.