Police detained nine party members and raided its offices in the northern lakeside town of Musoma to block a planned symposium by the youth wing on constitutional change, Chadema said in a statement on Saturday.
“We strongly condemn this blatant violation of the constitution and rule of law, sowing the seeds of hatred, discrimination and discord within communities,” it added, protesting against the “suppression of democratic rights” by police and other security forces.
Mbowe has been behind bars since July 21 when he was arrested along with a number of other senior Chadema officials hours before they were to hold a similar forum on calls for a new constitution.
He is due to appear at the High Court again on Monday, although his trial has been held up by legal wrangling, with his defence team most recently challenging the legality of the charge sheet.
“The president has instructed that people should now focus on economic development … So such conferences will have to wait,” Tibishibwamu was quoted as saying by local media.