The African National Congress (ANC) on Monday sent its "revolutionary well wishes" to Winnie Madikizela-Mandela as she celebrated her 80th birthday.

ANC spokesperson Zizi Kodwa said Comrade Winnie was a "fearless freedom fighter, stalwart of our movement and mother of the nation".

She remained the embodiment of the resilience and tenacity of South Africans.

"As a movement and a people, the ANC owes an enormous debt of gratitude to Comrade Winnie and her generation of freedom fighters who were an unshakeable mark and unwavering beacon of hope during the darkest days of our history."

She was resolute when the release of political prisoners, the return of exiles and freedom seemed unrealistic.

"Her selflessness and dedication kept the vision of freedom alive and added further pressure which ultimately saw the defeat of the apartheid regime."

The party wished her health and many more years of life.

Madikizela-Mandela was born in the Eastern Cape in 1936.

Celebrations for her milestone started earlier this month, with a birthday dinner at the Mount Nelson Hotel in Cape Town, attended by political bigwigs such as Cyril Ramaphosa and Julius Malema.

This was followed by a concert in her honour at the Artscape Theatre.

President Jacob Zuma thanked her on Monday for remaining unwavering in standing with the poor and downtrodden.

"We are grateful for the gift of your life. We wish you a happy, warm, enjoyable birthday today. May you have many more and continue to serve as an inspiration to the whole nation, especially the youth," he said.