With next year's general election looming, Tanzanian authorities have found themselves grappling with an emerging political force, ACT-Wazalendo, a small opposition party which has been boosted by the defection of Zanzibar's most prominent opposition figure.

Seif Shariff Hamad, a stalwart of Zanzibar politics for the past three decades, defected from the Civic United Front (CUF) on March 18 in protest against the High Court's dismissal of his petition challenging the legitimacy of Prof Ibrahim Lipumba’s chairmanship of the party.

As hordes of CUF supporters joined Mr Hamad on the journey across the political divide, the move was widely seen as a masterstroke by ACT-Wazalendo, and especially its leader Zitto Kabwe, strengthening its political base in a key part of the country ahead of the 2020 general election and this year’s civic election.

CUF branches in Zanzibar and Pemba, a CUF stronghold, are being turned into ACT-Wazalendo branches, with the CUF protesting the takeover of its properties.

The ensuing wrangle appears to lay the foundation for Mr Kabwe to challenge President John Magufuli and the ruling CCM party's virtual stranglehold on the top seat, in tandem with Mr Hamad launch of a campaign for the Zanzibari presidency.

Mr Hamad has been defeated in five bids since the first multiparty election in 1995. Is this his big break?

But the Registrar of Political Parties has come in to rain on the Zitto-Seif parade, threatening ACT-Wazalendo with deregistration over alleged violation of the Political Parties Act.

In a March 25 letter signed deputy registrar Sisty Nyahoza, the Registrar of Political Parties Francis Mutungi listed several offences, including pro-Hamad supporters in Pemba Island burning CUF party flags and replacing them with ACT-Wazalendo’s flags.

"The action of burning political party flags is in violation of section 11C of the Political Parties Act," the letter said.

An amended version of the clause passed a couple of months ago says convicted offenders are liable to fines of between Tsh1 million ($432.8) and Tsh5 million ($2,164) or 6-12 months' imprisonment.

Mr Mutungi also cited a video clip doing the rounds on social media that shows alleged pro-Hamad supporters shouting “Takbir!” while hoisting the ACT-Wazalendo flags. He said this was in violation of other clauses in the legislation that prohibit political parties from promoting religious biases among their members.

Another alleged offence cited by the registrar was the party's failure to submitted audited accounts of financial income and expenditure for the year 2013/14.

Although Mr Mutungi gave ACT-Wazalendo until April 8 to defend itself, indications of increased state animosity against the party were further manifested on Wednesday when police moved in to break up an internal meeting of the party's top hierarchy, convened to discuss how to set up their defence.

Both Mr Kabwe and Mr Hamad were present at the meeting.

The apparent battle of wits now being waged between the state and ACT-Wazalendo has served to relegate both the country's recognised main opposition parties CUF and Chadema to the back burner, at least for the time being.

While President Magufuli continues to be seen as a virtual shoo-in for re-election next year – thanks in no small part to his administration's systematic squeezing of political and democratic space – there is still much interest in how the opposition is shaping up for Zanzibar's presidential polls, when incumbent Dr Ali Mohammed Shein will leave after the constitutional two terms in office.

Until the Registrar of Political Parties' intervention, it was Mr Kabwe who looked to be the bigger beneficiary of this partnership by offering him and his party more leverage over Chadema and other opposition parties in the mainland (Union) political arena.

Mr Hamad's shift to ACT-Wazalendo, along with hundreds of his supporters, has been described as “seismic,” especially for Zanzibar where CUF, under his watch, has remained the undisputed alternative to CCM for over three decades.

But while his alliance with Mr Kabwe has weakened CUF's position in this sense, it remains to be seen how it might help his own chances of finally defeating the ruling party's next candidate for the Isles’ presidency on his sixth bid.