Growing tension in Zanzibar following the collapse of talks on the cancelled elections on the Isles is raising fears of divisions that could plunge the archipelago into an economic crisis.
In the dispute between opposition party Civic United Front and the ruling Chama cha Mapinduzi, CUF has threatened mass action should the Zanzibar Electoral Commission (ZEC) rerun the October elections.
CUF wants Union President John Magufuli to lead the talks, accusing Zanzibar President Mohammed Shein of lack of objectivity and favouring a rerun.
The party boycotted last Tuesday's 52nd anniversary of the Zanzibar Revolution, at which CCM supporters controversially displayed racist placards. The ruling party later issued an apology.
Tourism, a leading economic sector employing almost half of all Zanzibaris, is stable but political analysts see the situation as a reflection of Zanzibar's unresolved past. More than 2,300 people fled Zanzibar to Kenya and 30 were killed in political clashes in 1995 and 2000.
Dr Alley Nassor, a senior lecturer at Zanzibar State University on Pemba Island, says elections invariably come with an economic cost for Pemba, adding that the island is already marginalised for supporting CUF.
Unlike when Amani Karume became president after the 1964 revolution and set aside resources for Pemba, he said, the past 40 years have seen the island struggle economically and its residents locked out of civil service.
"People were throwing faeces into boreholes owned by political rivals," said Dr Nassor. "Asian university students were not given scholarships to pursue higher education abroad and were thrown out of state jobs in favour of black Zanzibaris.
"What is happening is a replay of several years ago. I think donors could cut aid and investors put their plans on hold."
In Zanzibar, CCM is seen as originating from the Afro-Shiraz Party (ASP) while CUF is regarded as a revival of the Zanzibar Nationalist Party (ZNP).
ASP was dominated by black Africans, previously slaves and clove pickers, mainly from Unguja. ZNP mainly comprised Arabs, Indians and Comorians, mainly from the pro-CUF Pemba.
"Recent statements by the majority of donors that the suspended October election was free and fair and calling on the Zanzibar Electoral Commission to announce its outcome means that they could suspend aid," said Dr Nassor. "That is exactly what happened in the past."
A cross-section of Zanzibaris of diverse political affiliations have in recent months joined hands to demand the autonomy of Zanzibar, with CCM accusing some of its senior members of supporting the opposition agenda and sabotaging the party.
The youth wing of CCM (UVCCM) this week called for the termination of former president Abeid Amani Karume's membership allegedly for supporting the opposition to weaken CCM.
"If CCM doesn't kick him out of the party, we will find other ways to punish him for sabotaging our party," said UVCCM national chairman Sadifa Juma Khamis.Of late, Mr Karume's family has been critical of the Union, leading to criticism by CCM members.