A federal mediator yesterday was assigned to stalemated negotiations between Woodward and Lothrup and Local 400 of the Retail Store Employees Union.

The apparent federal role in the talks comes just one day after about 1,500 union members unanimously voted to strike Woodies if an agreement cannot be reached by Sunday at 12:01 a.m.

In the meantime, Local 400 President Thomas McNutt said the union is arranging to bring in about 100 staff members from other cities to coordinate strike activities.

"The only thing that could delay some action would be the company demonstrating that they trust us in the negotiations," McNutt said.

Woodies Chairman Edwin Hoffman remained firm in his resistance to what has become the key union demand -- a closed shop for Woodies' workers.

McNutt and his representatives say they are committed to have a closed shop which would force all Woodies workers to join the union.

Hoffman, on the other hand, said yesterday that "my concern is the employe," and noted that many Woodies' employes have told him that they do not want to be forced into compulsory union membership.

Hoffman, on the other hand, said yesterday that "my concern is the employe," and noted that many Woodies' employes have told him that they do not want to be forced to join the union.

Hoffman said that the Federal Mediation and Conciliation Service was planning to send a representative to contact both sides in the dispute.

After an extensive effort, Local 400 won the biggest union organizing vote in the area's history in July, winning representation by a 4-to-1 margin.

Before that time, the company's workers had been represented by an independent, union, a group whose contract expired on June 30.

The two-month old negotiations had been going smoothly during their opening sessions. But, both McNutt and Hoffman say they have not been able to budge on the sticky closed shop question.

Hoffman said the issue presents a particularly difficult situation for Woodies, whose employes are frequently transferred from Maryland and the District to Virginia, where a right-to-work law forbids the closed-shop set-up.

Talks broke off last Wednesday over the union membership issue and McNutt said he believed the union is capable of shutting down the department store chain, even though it represents only about 1,500 of the 5,500 Woodies' employes.

"We could close down their warehouses overnight," McNutt said. "The warehouse is pretty militant. Most of the drivers have worked somewhere where a legitimate AFL or Teamsters sections exists."

McNutt said he was happy with the turnout at the Sunday meeting, noting that many of the employes who did not attend are part-time workers.

McNutt also said the possible strike has the support of Virginia and Maryland branches of the AFL-CIO and the sanction of the Washington Central Labor Council.

Both McNutt and Hoffman said they would support the presence of federal mediators to attempt at least to return to the bargaining table.

"We're available to meet around the clock," McNutt said. "We don't strike any employer for the sake of having a strike."

There are 14 full-service Woodies' stores in the metropolitan area.