The coalition, the Civil Society Organisations Directors Forum, made up of 65 influential rights groups from across the East African nation, said they had watched with alarm the deterioration of rights over the past two years.
“Democratic rights, freedom of assembly and association is getting worse,” the group said in a joint statement, released late Monday.
“For us, this situation can be viewed as a threat to national unity and disruption of national peace.”
Critics say Magufuli has unleashed a wave of oppression since his election in 2015, cracking down on opposition figures.
“Leaders should respect national laws and the constitution,” the statement read, saying the security forces should ensure “political meetings are protected, instead of banning and disrupting them.”
The police were “suppressing multi-party politics”, the group said, noting that “internal meetings of opposition parties have been attacked or banned.”
They also called on Magufuli to hold talks directly with opposition parties and leaders, warning of “restrictive” laws on parties they said violated the constitution.
The group includes the Legal and Human Rights Centre (LHRC) and the Tanzania Human Rights Defenders Coalition (THRDC), both key civil society groups, as well as organisations from Zanzibar, the semi-autonomous Indian Ocean archipelago.
All said they were concerned that a deterioration in basic rights would undermine peace in Tanzania, and wanted to raise a red flag warning that the country was headed in the wrong direction.
“Being citizens of the United Republic of Tanzania, with a constitutional duty to protect national solidarity, unity, justice and peace, we have seen it advisable to speak up and advise our political and government leaders,” the statement read.
“Our fear is that, if this condition persists, we will build a nation with a big group of people who feel that they have been excluded and discriminated,” it added.
Last month, Freeman Mbowe, head of Tanzania’s main opposition party Chadema, condemned what he described as a climate of fear installed by a “police state” after he was held in prison for more than three months.