The union representing active and retired county police officers said Thursday his union will also oppose a currently before the Maryland General Assembly.
Cole Weston, president of the Fraternal Order of Police Lodge 4, said he sent a letter opposing the bill to legislators representing the county.
"These career employees made a decision based upon state law that the county is seeking to change," Weston wrote in the letter. "It is inappropriate to subject them to a modified calculation."
County officials say the bill could by overturning a court ruling that said it was charging too much for a penalty on interest on pensions to retirees who transferred their state pension time into the county retirement system.
Weston, in an interview, said it is not uncommon for officers from state agencies to transfer to the Baltimore County Police Department.
Weston said the bill took him by surprise and he was working to determine exactly how many members were affected.
The county estimates that at least 150 employees will be affected.
Weston and John Ripley, president of the Baltimore County Federation of Public Employees, both say the number could be higher.
The Baltimore County Federation of Public Employees represents corrections officers, sheriff department deputies and other county employees.
Ripley is scheduled to testify before the Baltimore County House delegation Friday morning.
So far, only the union representing county fire fighters has backed the bill
Michael Day, president of the Baltimore County Professional Fire Fighters, testified Tuesday before the House Appropriations Committee in favor of the bill.
Day also sits on the Board of Trustees of the Employees' Retirement System.