Prince George's County officials have turned to workers recently laid off by the D.C. government, private contractors, temporary hires and volunteers to take over the work of striking public employes.

In the county's hardest hit department -- Corrections, where 120 of 126 jail guards walked off the job and then were fired -- officials set up interviews with jail guards recently fired in the District's budget crunch and continued efforts to hire a private security company to take over jail operations.

As the county's first public employe strike enters its fourth day today, the possibility of a resolution emerged as County Executive Lawrence J. Hogan agreed to meet with a federal mediator this morning. Hogan has refused to take a personal hand in any of the negotiations with the five striking locals in the American Federation of State, County and Municipal Employees.

In addition, county and union leaders will meet this afternoon with the mediator in an effort to reopen negotiations in the 18-month dispute. Both sides stressed that the 2 p.m. meeting did not signal a resumption of negotiations.

While the two sides agreed to meet, they continued to argue yesterday over the strike's effectiveness and impact.

The county released figures claiming that 687 workers out of 1,500 union members were off the job, 27 fewer than Wednesday. Union leaders maintained that 1,375 employes had signed up to walk picket lines in four-hour shifts around various county facilities.

Whatever the actual figure, most county offices continued to operate yesterday, but with skeletal staffs in many cases. In several instances -- at the county animal shelter, landfill and other public works offices -- work had all but stopped.

In an effort to continue county services, officials have moved employes around within departments and between them to "plug" gaps in service.

They have also turned to employes hired on a temporary basis over the last few months, officials said. Many of these temporary workers were brought into county government after the union first threatened to strike several months ago and county officials began plotting strike emergency strategy.

Hogan press aide Stephanie Bolick said the county has also received a number of calls from county residents who have volunteered their services, and some of them have come to work.

At the county's senior citizen housing projects, according to one resident manager, workers have been hired through private maintenance companies to replace striking employes. At the jail, officials obtained a list of 200 recently fired D.C. jail guards and began contacting them.

Spokesman James O'Neill said yesterday that jail officials are also talking to three private firms about providing jail security.

Union officials said they doubted whether former District guards or private ones would be willing to cross the AFSCME picket line outside the jail. "We view them as scabs if they do," said one union member.

Since early Tuesday, when county jail guards walked off the job and inmates rioted, state police have been guarding the jail.

O'Neill said the jail routine has returned to normal and most damage from the riot has been repaired. County officials yesterday reviewed the damage estmates from the riot from $50,000 to $15,000.

The status of the jail guards whom Hogan has fired is likely to have a large impact on any resolution of the strike. Just as Hogan is adamant in his refusal to rehire the striking guards, the union insisted yesterday that its members would not come off the picket line without them.

In a related development yesterday, Circuit Court Judge James M. Rea postponed until Monday a contempt of court hearing against about 60 jail guards who failed to heed a court injunction to bar them from striking.