The Montgomery County Council tentatively approved 4 per cent cost-of-living raises for both county and school employees yesterday despite a contract that calls for giving school employees 6 per cent raises.

The Council's decision is expected to stand when it takes final action on the county budget on Monday.

But the county school board, which negotiated the contract with school employees, could decide to honor that contract's 6 per cent raise provisions, finding the funds to pay the extra 2 per cent by taking money away from some school programs or reducing the number of employees.

School Board president Herbert Benington said "I'm not sure how good a chance there is' for providing the full 6 per cent raises, "but here is a chance."

The raises approved for county government and Montgomery College employees will be partly offset because those employees will have to make higher contributions to their insurance.

County Executive James P. Gleason, who recommended the 4 per cent raises said the Council's decision to make employees contribute more to their insurance "will have a devastating effect on county government employees' pocketbooks.'

County government and Montgomery College employees have been contributing 20 per cent and 9 per cent, respectively, of the cost of their insurance. The Council's action will raise the contributions to 29 per cent, the percentage already paid by school board employees.

If applied uniformly to all county government employees, the higher insurance contributions would reduce raises to only per cent. The Council recommended that Gleason prorate the insurance payment increase, requiring higher-paid workers to pay a greater share.

Yesterday's budget decisions were made in an emotional atmosphere.

In strongly-worded pleas, council members Norman Christeller and Esther Gelmen, along with School Supt. Charles M. Bernardo and school board members, argued for honoring th negotiated 6 per cent raises.

Those raises were agreed to after tough negotiations, they said, and county teacher's salaries have fallen behind those in the rest of the Washington area. They said the quality of education would be jeopardized if the school board had to take $3 million or $4 million from its own budget to fund the raises.

The Council has cut $2 million from the $261 million budget the school board proposed, eliminating such things as interscholastic sports in junior high schools and 105 summer teaching positions.

"Don't force us to choose between our employees and our children," said Supt. Bernardo.

But Council President John Menke and members Jane Ann Moore, Neal Potter and Elizabeth Scull said they could not support the 6 per cent figure. They cited the county's tight fiscal situation and opposition to a property tax increase that 6 per cent raises would necessitate.

Moore shook her head and declared: "The longer we speak, the sadder we are."

Menke added, "Next year it'll be worse."

If the 4 per cent figure stands, the school board will have to re-enter negotiations with the Montgomery County Education Association, which represents 7,000 teachers, and the Montgomery County Council of Supporting Services, which represents 5,000 other school employees.