A previous attempt to change the constitution failed in 2014, after a draft document proposed to reduce presidential powers and establish an independent electoral body.

On Wednesday, CCM spokesperson Shaka Hamdu Shaka said the party's top body was "insisting" on a need to have a new constitution.

He said the party was supporting President Samia Suluhu's reconciliation efforts.

Since 2014, the main opposition party Chadema and other parties have been pushing for a new constitution, which has seen their leaders and supporters have run-ins with the authorities.

Some have been detained several times for holding meetings on a new constitution - including Chadema chairman Freeman Mbowe, who was arrested last July and held for seven months in custody.

Former President John Magufuli, who ruled from November 2015 until his death in March last year, had declared there would be no constitutional reforms while he was president.

Opposition rallies were restricted during his tenure.