The Congress of South African Trade unions (Cosatu) feels betrayed by the marriage between the Democratic Alliance (DA) and the Economic Freedom Fighters (EFF), president Sdumo Dlamini has told journalists.

"You are looking at the combination of the odds which have enjoined at one point [to] ensure the ANC [African National Congress] does not stay in power... They even say they are happy with the devil. We feel betrayed because some of the parties... we voted for them on their ideological outlook."

Dlamini said the EFF has abandoned the principal and ideological outlook as a left formation.

He questioned how the DA and the EFF would handle a call for the ban of labour brokers or a national minimum wage.

"Who loses the worker? What you have deposited yourself to be in society wearing a red helmet, but at the alter of expediency you denounce that principle and workers suffer."

Dlamini, however, admitted that the federation was not at its best during the campaign for the local government elections.

He said a weaker alliance found itself in disarray and lacked the "required coherency" in applying strategy and tactics.

"All this combined with increasingly united counter-revolutionary forces comprising of white monopoly capital. Political opposition supported by western imperialism has placed our revolution on a crossroads," Dlamini said.

EFF leader Julius Malema announced earlier this month that the party would vote with the DA in hung municipalities, which resulted in the ANC losing control of three key metros.

Explaining its decision, Malema said the DA was a better devil than the ANC.