The South African Communist Party (SACP) has voted two key members of President Thabo Mbeki's cabinet off the party's central committee.

Essop Pahad and Jeff Radebe failed to get enough votes to retain their seats on the committee at the SACP congress at the weekend.

The communists are part of the governing alliance with the African National Congress and the Congress of South African Trades Unions (Cosatu).

The Business Day newspaper says that the vote was a setback for the president as the ministers were "embarrassingly defeated".

Charles Nqakula was re-elected as SACP chairman

It says the elections for the committee "come in the wake of increasing tension between the SACP and it alliance partner, the ANC, apparently underlined by Mbeki's decision not to attend the SACP's annual conference".

Other ministers in the cabinet retained their places - including Safety and Security Minister Charles Nqakula and Water Affairs Minister Ronnie Kasrils. Mr Nqakula was also re-elected as SACP National Chairman.

"Governmentalists"

The failure of Public Enterprise Minister Radebe and Minister in the President's Office Pahad to retain their seats has been described by the Johannesburg Star newspaper as a "purge".

It said that "ultra-leftists" within the party campaigned against the them and against Public Service and Administration Minister Geraldine Fraser-Moloketi. She decided not to stand for re-election.

Business Day said that the defeats for Mr Radebe and Mr Pahad appeared to be party reaction against the performance of particular ministers in government rather than against SACP participation in the government.

Some delegates to the SACP congress described those who lost their places as "governmentalists".

Water Affairs Minister Ronnie Kasrils, who gained the second highest number of votes of those re-elected, said that party members needed to know that party members who were part of the government had to support government policy in total, even if it conflicted with SACP positions.

"If you are a communist and become a member of parliament under the ANC and you become a minister appointed by the president, you cannot expect that the MP or minister is simply going to articulate party policy.

"The alliance with the ANC and our acceptance of the election ticket is not qualified," he said.

Against privatisation

The ANC-SACP-Cosatu alliance has come under strain over issues such as privatisation of publicly-owned institutions and assets and workers' pay.

Earlier in July, municipal workers went on strike over pay and staged protest marches in Johannesburg.

Will the president see red over SACP vote ?

Prior to the start of the congress, the SACP leadership rejected press reports about poor relations with the ANC and issued a statement stressing the strengthening of the alliance.

But the statement also called for the "retention of public ownership over parastatals".

In May, Jeff Radebe was the minister who announced deals for the privatisation of a large stake in the state-owned arms company Denel.

The Star said that the SACP vote against the ministers could lead to ANC action against "ultra-leftists" at its conference later this year.