They say they will discuss and take action against the decision contained in the middle-term economic vision presented by prime minister Ranil Wickremesinghe last week.
Leaders of trade unions in the state, semi-government and private sectors say they strongly oppose the decision taken without being consulted.
Convener of the state, semi-government and private sector trade unions federation Kesara Kottegoda Vithana said the World Bank and the IMF have been pressurizing the government to invest money belonging to the EPF, the biggest fund in South Asia, in the private sector.
In order to do so, Mahinda Rajapaksa tried to change the laws, but failed due opposition by the working people, he said.
But, Rajapaksa and Ajith Nivard Cabraal had defrauded the fund.
The present government too, is trying to change the laws by claiming to make the two funds safer.
Handing over responsibility to parliament is not the real solution, he said.
TU leaders said the National Labour Advisory Council would meet and discuss how to make their opposition known.
They have also decided to inform the prime minister in writing about their opposition to merge the two funds.
Since workers have the absolute rights over the EPF and the EPF, they should be consulted when taking any decision.
Their representatives should be part of the administration process and action should be taken against the fraud that has taken place, said TU leaders.
Meanwhile, a decisive meeting will take place with regard to this issue, attended by the TUs and the PM.