Young Communists League leader Buti Manamela said Mbeki and Tshabalala-Msimang denied hundreds of HIV-positive people access to antiretroviral drugs when they were in government.
Without mentioning their names he said "people" who presided over government as president and minister of health were responsible for the many ongoing HIV/Aids deaths because of their denial of the existence of the virus.
"Those who have denied the existence of HIV/Aids must be brought before the commission and tried for genocide," he said.
Manamela lauded President Jacob Zuma for his stance on the HIV/Aids pandemic and lashed out at Mbeki and his administration's officials.
"We cannot have a situation where people continue to die because of those who presided over government as president and health minister and who refused to provide antiretrovirals.
"People who refused to accept the existence of HIV/Aids also refused to save our nation.
"We can't have people who are responsible for many deaths, but who continue to enjoy the benefits of the companies that the government is still doing business with," said Manamela.
He was addressing at least 1000 SACP supporters yesterday at the local stadium just outside Rustenburg, North West, at a rally to mark the closing of the party's Red October Campaign.
The rally was also attended by Blade Nzimande, the SA Communist Party secretary general, Cosatu general secretary Zwelinzima Vavi, ANC deputy secretary-general Thandi Modise and the provincial SACP and Cosatu leaderships.
Over a week ago, when addressing the National Council of Provinces, Zuma warned about the growing number of people dying as a result of the pandemic.
Manamela said the YCL was happy that the proposed National Health Insurance will provide free "circumcision" for young people at the public hospital.
"It [free circumcision] will reduce the risk of contracting HIV/Aids.
"We don't say it will prevent HIV/Aids, but it will reduce it," he said.
Manamela accused labour brokers of being "modern-day slave-owners and lazy bums, who are too lazy to work like everyone else".
Meanwhile, Vavi also criticised employers for misleading the country - for saying that if labour brokers are scrapped half a million jobs would be lost.
Manamela also took the opportunity to attack the ANC secretary general, Gwede Mantashe, for saying that Cosatu members in the public sector are delivering "shoddy service to communities".
He said: "We don't agree with the statements attributed to the ANC secretary general.
"We hope he was not wearing the Communist cap on that day when he said the public service servants are overpaid and under-performing.
"We believe that you need to reward public service servants as much as you expect better service," said Manamela.
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