The ANC has accused those who prevented President Jacob Zuma from speaking at union federation Cosatu’s main Workers’ Day rally of reducing the significance of the day by their “unacceptable behaviour“.

“As a result‚ the important issues of workers’ rights‚ the advancement of the living wage and decent work were overshadowed by narrow factional interests‚” ANC spokesman Zizi Kodwa said on Tuesday.

Speeches at the official rally‚ held in Bloemfontein on Monday‚ were cancelled after workers heckled and booed Zuma and Cosatu president Sdumo Dlamini. ANC deputy secretary-general Jessie Duarte and chairwoman Baleka Mbete were also heckled at rallies held in Limpopo and KwaZulu-Natal respectively.

ANC deputy president Cyril Ramaphosa was given a warm reception in Mpumalanga where he addressed the provincial Workers’ Day rally. Cosatu has officially endorsed Ramaphosa to take over as president of the ANC.

In April‚ the union federation — which was among Zuma’s main backers as he ascended to power — called on him to step down‚ saying it no longer believed that he was the best person to lead the ANC and the country. Last week‚ two Cosatu affiliates — the National Education‚ Health and Allied Workers Union and the Communication Workers’ Union — said they did not want Zuma addressing the rally.

The ANC has condemned the behaviour at the rallies. “The strength of the revolutionary movement and our alliance has always been the management of intra-organisational contradictions ... between the alliance partners‚ guided by the highest levels of revolutionary discipline‚” Kodwa said.

He also said the ANC would double its efforts to foster unity within the movement and the alliance: “Public displays of disunity broker no victors and only serve to weaken the alliance as a whole.”