Some sang for President Jacob Zuma, some for his likely opponentKgalema Motlanthe.

When the National Union of Mineworkers and South African Democratic Teachers' Union tried to get the congress to discuss the issue of the ANC leadership, they were shot down.

Cosatu secretary-general Zwelinzima Vavi said the matter has been referred to the federation's central executive committee and could not be discussed by congress.

Earlier, ANC secretary-general Gwede Mantashe showed his support for a second term for Zuma when he referred to a "Zuma moment" instead of a "Lula moment" as called for by Cosatu.

The "Lula moment" is a reference to former Brazilian president Lula da Silva, who failed to please workers during his first term (2002-2006) but turned the country around during his second term (2006-10), dramatically improving the economy and creating hundreds of jobs.

Mantashe said a "Zuma moment" could be achieved with Cosatu's help, particularly in ensuring that agricultural land was used optimally.

Lula introduced radical economic policies that reduced inequality, poverty and unemployment.

Cosatu is proposing the government follows the same direction.

"We agree with the thrust of the socioeconomic document of Cosatu's central executive committee, but we want to add a few issues and their contribution to make the Zuma moment a reality," he said.

"Cosatu must join the ANC in [sifting] out what minerals should be nationalised as the discussion will be key in Mangaung," Mantashe said.

Earlier, delegates showed deep divisions over whether to support Zuma or Motlanthe ahead of the ANC's elective congress in December in the Free State.

While some affiliates broke into pro-Zuma songs, others called for change - using the substitution signs seen at soccer matches.

Two groups marched around the hall trying to outdo each other.

There were conflicting positions among members from the National Union of Metalworkers, with some shouting "sifuna uKgalema" (We want Kgalema).

One member danced on top of the table and held up a framed photograph of Motlanthe.

Vavi took to the podium and asked affiliates not to bring discord and division to the congress.

"There is nothing wrong with the singing about any leader of the alliance but it is wrong to show signs. Once you show signs, you divide the congress," he said.

At one point, National Union of Mineworkers secretary-general Frans Baleni held up a V-sign for victory as he and Cosatu president Sdumo Dlamini danced next to Vavi.

Vavi's call for members to stop making signs was met with a lukewarm response by those keen to have the leadership debate dealt with .

Dlamini charged to the podium and pleaded with delegates to stop the commotion.

"The Chiefs and Pirates signs must stop now. Please take your seat," he said after which order was restored.

The congress had resolved on Tuesday to defer political discussions to the central executive committee for deliberation.