The ANC's stance on the youth wage subsidy showed that Cosatu was controlling the alliance, the DA said on Thursday.
"The secretary-general of the ANC Gwede Mantashe has now come out against the youth wage subsidy," Democratic Alliance MP Tim Harris said in a statement.
"This is the latest indication that Cosatu [Congress of SA Trade Unions] is calling the shots in the tripartite alliance, and seriously undermining President Jacob Zuma's authority."
According to a report in Business Day, Mantashe said the R5 billion set aside for the youth wage subsidy should be "accessible" to fund "other interventions" to alleviate youth unemployment.
In 2010, Zuma announced that the government would table a proposal to subsidise the cost of hiring younger workers, to encourage firms to take on inexperienced staff. This was budgeted for by Finance Minister Pravin Gordhan in that year's budget.
Harris said just minutes after Zuma's speech, Cosatu general secretary Zwelinzima Vavi told reporters that he objected to the subsidy.
"It is a sad state of affairs that today the president's proposal has been shelved, while Mr Vavi's opposition to the policy has prevailed. The direct cost of this is borne by the more than 400,000 young people who will not benefit from the subsidy," said Harris.
The youth wage subsidy was formally rejected at the African National Congress' policy conference in June.
Harris said the final nail in the coffin came when Mantashe said that the R5 billion budgeted for the subsidy should be used to fund other initiatives.
"It is now clear that Cosatu's authority in the tripartite alliance trumps the needs of our most desperate citizens -- the unemployed young people -- who simply want an opportunity to get a foot onto the employment ladder," he said.