Prince George's County police officials told police union members last night that County Executive Parris N. Glendening will lay off 160 or more officers unless the union agrees to forgo a scheduled pay raise, union President Darryl A. Jones said.

County firefighters also were told yesterday that they will face layoffs of 60 to 75 people if they take the scheduled pay raise, firefighter union President Ron Milor said.

Police union members indicated that they will fight the pay cut and the layoffs, while the firefighter union is expected to defer the pay raise for nine months to avoid layoffs, union officials said.

Jones said the board of Fraternal Order of Police Lodge 89 rejected the county executive's request to forgo a 7 percent pay raise. "We're not giving up the money we worked hard for, and we're adamantly opposed to even one police officer being laid off," Jones said.

The layoff of 160 to 230 officers, projected by budget officials, would eliminate staffing gains the county has made over the past year. An ambitious hiring plan began in May 1989 after it was reported that the department was so understaffed that as few as 51 officers at any one time were patrolling the entire county.

Glendening already has canceled plans to add 200 police officers to the force, now at about 1,200 members, by June.

Milor said officials of Prince George's Professional Firefighters Local 1619 will ask members to wait until April 1992 for a pay raise that is scheduled for July. In return, Milor said, the county had agreed to add a "no layoff" clause to the current contract.

"I am truly convinced the county executive has no choice, considering the current economic climate," said Milor, who represents the 680-member firefighter union. "We look at this as giving the county a loan for nine months."

Earlier this week, Glendening said county officials were exploring "all options," including layoffs of public safety personnel, in an attempt to compensate for a $72.3 million reduction in revenue. Laying off people or eliminating the pay raise would save an estimated $5.5 million in the police budget.

Jones said the police union will be looking at other ways to cut expenses and reduce waste in county government.