Tsvangirai's final months were accompanied by increasingly public quarrelling between his three deputies over who would succeed him as head of the Movement for Democratic Change (MDC).
The party - which has a history of splintering - had been trying reunite to fight the coming election, but the death of its widely-admired founder triggered renewed rivalry.
Fresh divisions could mean that President Emmerson Mnangagwa and the ruling Zanu-PF face little opposition at the election, which is expected before July.
Voters will go to the polls for the first time since Robert Mugabe, who ruled Zimbabwe with an iron fist since 1980, was ousted in November after a military intervention.
"We are going to see a major split in the MDC now that Tsvangirai, who was the glue that held the party together, is gone," Harare-based political analyst Alexander Rusero told AFP.
The latest bickering came to a head when one of the deputy leaders, Nelson Chamisa, called a meeting at MDC headquarters in Harare the day after Tsvangirai's death.
Chamisa had supposedly been named as the interim MDC leader by Tsvangirai as he underwent cancer treatment in South Africa.
Hundreds of party activists gathered outside the building to honour Tsvangirai - but without the party's other deputies, Thokozani Khupe and Elias Mudzuri.
A furious Khupe lashed out at Chamisa.
"Tsvangirai dies and you go on with a meeting to appoint yourself as leader. How shameful!" she told the local press.
"You are power-hungry. You can't even wait for two days to have Tsvangirai buried."
Shortly before Tsvangirai's death, Mudzuri visited him in hospital in Johannesburg to establish his own claim to be the rightful heir.
"It is myself and no one else," Mudzuri told South African television. "People must respect authority as given by my president and make sure they work towards... winning the 2018 elections."
In turn, Chamisa has called for the party to unite and be disciplined.
Chamisa is thought to have the largest number of supporters. Many analysts tip him to emerge as the MDC's next leader and say he could manage to head off a permanent split.
The MDC once posed a formidable challenge to Zanu-PF, even winning the first round of a presidential election in 2008 vote.
Tsvangirai then pulled out of the run-off after a wave of deadly violence unleashed by Mugabe supporters, and the MDC entered into a troubled coalition government.
Under relentless pressure from Mugabe's regime - and the threat of intimidation and violence - the MDC have suffered major splits since Tsvangirai founded the party in 1999.
But Tsvangirai last year reunited with his former allies Tendai Biti and Welshman Ncube, who both left Tsvangirai's wing of the party, to run together in the 2019 elections.
Now the party could struggle to launch a credible election challenge to Zanu-PF, which is often accused of decades of brutal repression and overseeing the collapse of Zimbabwe's economy.
"These games are being played during this dark period of mourning. I see a weaker opposition and a weaker MDC," Eldred Masunungure, a political scientist at the University of Zimbabwe, told AFP. Tsvangirai's body is expected to return to Harare this weekend, ahead of his funeral next week.