(Bloomberg) --

Tanzania’s main challenger to President John Magufuli in this month’s general election has won the backing of a rival opposition party politician.

Zitto Kabwe, the head of ACT-Wazalendo, announced on Friday that he will vote for Tundu Lissu from the main opposition Chadema party in the Oct. 28 poll, despite his own party naming former foreign affairs minister Bernard Membe as its candidate.

Lissu, a human rights lawyer who survived an assassination attempt in 2017 and who returned to Tanzania in July from self-imposed exile in Europe, is seen as Magufuli’s main challenger. He has pledged to fight for fair and credible elections.

“I will vote for Lissu because he is the strongest presidential candidate that can defeat Magufuli in this historic election,” Kabwe told supporters at a campaign rally in the northwestern Tanzanian town of Kigoma, saying his decision should be regarded as guidance to all opposition supporters on election day.

Chadema and ACT-Wazalendo initially planned to formally announce Lissu as the joint opposition presidential candidate earlier this month, but the authorities said the move could breach a requirement that interested groups sign a coalition agreement at least three months before elections are held, and have it approved.

The Tanzanian president and his CCM party, which has ruled the country since independence from Britain in 1961, is expected to win re-election for a second term, but could face a serious challenge if the main opposition parties unite behind Lissu, according to analysts.

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