"The Solidarity Movement (Solidarity, AfriForum and Helping Hand) today announced that it would be moving investments and money market accounts from Absa to other banks," a statement read.
"The investment accounts of the respective institutions will be moved to FNB and Investec," AfriForum CEO Kallie Kriel said.
This was a day after they released a study that found that Standard Bank and Absa were the most expensive banks for individual accounts in the country, while Capitec and First National Bank were the cheapest.
The report compared the bank charges of various personal accounts at the four commercial banks -- Absa, Standard Bank, First National Bank, Nedbank -- as well as those at Capitec, with each other.
The union was also distributing its report to its members to allow them to make an informed decision about where to do their banking.
The union has denied that the move was a vendetta against Absa with whom it has recently clashed after the bank raised questions about transformation in rugby.
A controversial SMS surfaced in September in which Absa deputy chief executive Louis von Zeuner apparently requested that SA Rugby Union (Saru) president Oregan Hoskins look into the number of black players in rugby.
As a result, Solidarity threatened to take R18-billion worth of business away from Absa -- which is the biggest sponsor of Saru -- if it can't show that it won't interfere politically in sport.
The union said that it supported the advancement of black people in rugby, but were against big sponsors using financial muscle to interfere in the operational decision of rugby while it does not interfere in decisions of other sports.
The union has also recently taken issue with Standard Bank over staff retrenchments.