The ruling tripartite alliance is here to stay and is stronger than ever, Congress of South African Trade Unions (Cosatu) president S'dumo Dlamini told its tenth national congress on Monday.

"There are no hostile differences within our ranks as we speak to you at this time," Dlamini said in officially declaring the conference open at Gallagher Estate, in Midrand.

"The doomsday prophets... are now painfully swallowing their words," he said.

Dlamini said the African National Congress (ANC) was now back "to its right owners", and the South African Communist Party was stronger.

While there were differences, which would always be there, there were now overlaps in policy.

He said rural and skills development, as well as national health insurance, were now part of the government's programme.

Dlamini said the "1996 class project" - a name for supporters of former president Thabo Mbeki - had been defeated, but cautioned that it continued to struggle against the working class.

He warned that remnants of the project "inside State apparatus" were "encouraging capitalists not to be cowards".

The Mail & Guardian on Friday quoted Dlamini as saying Trevor Manuel was the last "hope" for the revival of the project.

He told the newspaper Manuel was using the planning commission to position himself as "second-in-charge".

"He wants to be seen again as this super-minister and every minister should go to him, bow his head and say, 'Please, Mr Manuel, can we have this?' " Dlamini was quoted as saying.

The ANC backed Manuel after Cosatu's criticism, saying "principles rather than individual personalities" should be debated.