There is strong campaigning within Zimbabwe's Movement for Democratic Change (MDC) for the top 12 positions in the party. Many analysts believe the MDC will win the next countrywide elections against President Robert Mugabe's ZANU-PF party.
Around the football stadium in a poor part of Bulawayo, more than 5,000 MDC delegates began gathering for the congress.
Many groups were campaigning for candidates seeking one of the top 12 spots on the party's national standing committee, which runs the MDC on a day-to-day basis.
Groups of supporters for various candidates were singing catchy campaign songs on the outside of the stadium. Other groups were handing out promotional material.
Only MDC President Morgan Tsvangirai, who is also prime minister in Zimbabwe's inclusive government, has been unanimously re-elected prior to the congress.
Tendai Biti, secretary-general of the MDC, and finance minister in the inclusive government, said it was remarkable that the party has survived since it was launched more than 11 years ago.
"To be alive in Robert Mugabe's Zimbabwe... Some of us have been tortured, some of us have been imprisoned, some of us have been exiled, we died 10 times over, to be here, in our third congress in spite [of] everything that has happened to us, I think is a miracle. So we deserve to celebrate," said Biti.
Biti has significant support to retain his post, but others, including well-known MDC provincial and national leaders are being challenged for the first time since the party's formation.
Biti said the stiff competition for top jobs is healthy, but he said it has also led to some regrettable intra-party violence.
"It is an extremely healthy party, the exuberant competition in all the provinces: that is democracy, but also there is a bad side that has come out of this - violence and other illegal practices. This is unacceptable. Also sometimes the victim becomes the perpetrator. We are in a very violent society because of ZANU-PF," added Biti.
In the 26-month-old inclusive government, Sekai Holland represents the MDC in a ministry created to promote national healing between victims and perpetrators of violence.
She said the MDC will have to confront the pre-congress violence and ensure that it never happens again.
"I have told Tsvangirai urgently we have to put a program together inside the party where we do national healing internally, meeting this dimension we were never aware of," said Holland.
Holland is standing for election as deputy treasurer-general. The present treasurer, Roy Bennett, who many say is the most persecuted member of the MDC, is living in exile in London, as he has been warned that if he returns to Zimbabwe he will be arrested.
He has made himself available, from exile, for re-election.
The congress is due to be officially opened Saturday by Kenyan Prime Minister Raila Odinga.