Cosatu has wished the ANC well on its 101st anniversary, in a letter to secretary general Gwede Mantashe.
Congress of SA Trade Unions (Cosatu) general secretary Zwelinzima Vavi wished the party "another 101 years of existence" in the letter, which was dated 8 January — the day of the anniversary.
"The ANC has for 101 years led our people and inspired millions more across the continent and the globe to fight for freedom and democracy," Vavi wrote.
"Guided by your primary principle of selflessness, you have been one of the finest examples of [a] progressive liberation movement."
Vavi said the ANC had survived because it had made a point of trying to alleviate poverty.
"It has been a voice for the voiceless. It has stood shoulder to shoulder with exploited workers," he wrote. "The ANC must continue doing that."
Vavi said this year also marked the centenary of the Native Land Act.
"We sadly mark the centenary of the... act which legalised theft of the land by an invading foreign army that occupied our country by force.
"No stone must be left unturned to reverse this ugly page in our history."
Vavi saluted those who had fought against apartheid in their youth, and the role played by "our mothers".
"These brave women led countless marches, often serving as an inspiration to the masses as [a] whole to fight not only against national oppression, but also against women's exploitation."
He said the working class had always been the backbone of the liberation struggle.
"We are particularly pleased to note that workers have always played a leading role and provided the finest leaders to the ANC," Vavi said.
"The history of the workers' struggles and those of the ANC are not separable."
Vavi said unity in the alliance between the ANC, Cosatu and the SA Communist Party was critical.
"We hope that the ANC will mobilise the majority of South Africans to realise all the objectives it set for itself in its national conferences, in particular for total economic emancipation.
"The next 101 years of the ANC must be characterised by heightened mass action for the total emancipation of black people in general and Africans in particular from economic bondage," he said.