The D.C. police department, at the direction of Mayor Marion Barry's office, yesterday halted plans to send provisional layoff notices to 204 police officers, apparently in anticipation that Congress will assure funds in the city's budget to avoid the layoffs.

The layoff notices, which tell officers there is a possibility they may be terminated Oct. 1, were scheduled to be distributed today.

But a high-ranking police official said yesterday there is now a "feeling that Congress will stipulate [in the city's budget bill] that no police officers be laid off."

This was an apparent reference to hostile remarks by key members of the House District appropriations subcommittee to the layoff proposal during city budget hearings Tuesday on Capitol Hill.

"I think it is a serious mistake," Rep. William H. Natcher (D-Ky.), the subcommittee's senior member and former chairman, told Mayor Barry. "I wouldn't reduce the police department one officer if I were in charge of it."

Rep. Carl D. Pursell (R-Mich.), the panel's ranking minority member, suggested that the subcommittee add language to the city's budget bill, requiring that the police force be kept at full strength.

Police officials pointed out yesterday that the 204 layoff notices were only provisional, warning the officers that some or all of them might be dismissed, depending on the number of voluntary retirements and other attrition factors helping to reduce the size of the financially strapped department.

If an actual reduction in force (RIF) is required, the affected officers will receive notices 30 days before their termination dates.

City Administrator Elijah Rogers said yesterday no layoff notices would be sent to any police officers until he and the city's acting personnel director, Jose Gutierrez, talk with Police Chief Burtell M. Jefferson about the RIF list.

"We want to go over the procedure," said Rogers, who said he plans to meet with the chief on Monday.

The police force now has 3,949 uniformed officers, a figure that would drop to 3,676 after Oct. 1 because of resignations, retirements and layoffs. Attrition is expected to bring the force down still further to 3,476 officers by Oct. 1, 1981, officials said.

The proposed cuts in the police department as well as those in other city agencies are needed, according to Mayor Barry, so the city can absorb higher costs for energy, payrolls, pensions and other items and still have a balanced operating budget of $1.5 billion in fiscal 1981.

But the police department cuts have alarmed city residents at a time when the crime rate is increasing.

The average daily number of reported major crimes in the city has gone up to 171 now compared to about 150 earlier this year, officials said. Armed robberies, for example, in the District have increased 19 percent so far this year over the same period in 1979.