"Our modern day detractors, from the comfort zone of their foreign-funded NGOs [non-governmental organisations] and academic institutions, criticise our principled alliance with the ANC. They say that we cling to the ANC," he said.

"When there were difficulties in the SACP-ANC relationship they celebrated, and accused us of behaving like a battered wife, and when the alliance is going well, as it largely is in the present, they complain that the SACP is exerting 'undue influence' over the ruling party."

Nzimande was speaking at a rally marking the SA Communist Party's 91st anniversary, at the Johannesburg City Hall.

He said the SACP's detractors claimed it lacked the courage to stand on its own in elections.

"Who are these fools who were nowhere to be seen in the course of the dark struggle days against apartheid-colonialism? Who are these hypocrites who now pretend to give us a lesson in courage?" he asked.

"Let us remind them that in the grimmest hours of struggle, communists were in the forefront of building the ANC, the very organisation that they now advise us to abandon," Nzimande said.

"We will not abandon the ANC. Together with principled revolutionaries, we will also not, and never, allow the ANC to be stolen by tenderpreneurs and agents of imperialism... No matter how much they insult us, history is on our side."

Nzimande read out a list of communists who died in the struggle against apartheid before criticising former president FW de Klerk.

Earlier in the week De Klerk said the spirit of inclusiveness and reconciliation embodied by former president Nelson Mandela was no longer prevalent in the country.

He said the SACP was one of the driving forces behind what he called "radical ANC policies".

"FW de Klerk should hang his head in shame. FW de Klerk must shut up. Say what you want to say [about the SACP]. We know you do not like us."

Nzimande, who also serves as the minister of higher education, said the late delivery of textbooks in Limpopo was as a result of the "deliberate tenderisation of the state".

"The publication of textbooks and their procurement should be a centralised function," he said.

"Instead, what we have is a system of rent-seeking go-betweens, suppliers of suppliers of suppliers, working with syndicates within our provincial line departments. Publishers themselves are making a killing."

He said the country should use the saga to transform the textbook publishing industry "whose core still remains that built by the National Party and the apartheid regime".

He also criticised the legal NGO, Section27, which took the department of basic education to court to force the delivery of textbooks.

"Going to court will not change the issue. The court can rule a million times, but if there is no structure [in the province] how can the books be delivered. People need to be mobilised instead."

He also criticised "professional cynics" who did not acknowledge the country's accomplishments.

"Those professional cynics, we tell them we are having swimming champions [in the Olympics], and they say 'yes, but you still can't deliver textbooks'," Nzimande said.

"Those people who pretend to be judges, who is judging them?"

He said the party wanted to see a united African National Congress ahead of its elective conference in Mangaung at the end of the year.

"Those who go with dirty money to the ANC -- as tenderpreneurs -- ahead of Mangaung, you will have to deal with the communists before the ANC. None of our organisations are for sale."

ANC national executive member and Justice Minister Jeff Radebe told the rally earlier that the ANC needed the SACP.

"They were the first truly non-racial movement in our country. We owe one of our own most important principles -- that of non-racialism -- to the Communist Party."

The Johannesburg City Hall was awash with the SACP's characteristic red and black colours, as members stamped their feet, sang songs and waved flags ahead of Nzimande speech.

At the foot of the stage were two large red cakes, surrounded by bottles of champagne.

Printed on the cakes were: "91 years of militant struggle for socialism" and "1921 - 2012".

The party celebrated it's anniversary on Tuesday.