Racing an April 30 deadline, the giant AFL-CIO Retail Clerks International Union is trying to organize more than 8,000 workers at Woodward & Lothrop, Washington's biggest department store chain.

At least 23 persons have been arrested as a result of the organizing campaign, which already has seen the union send 150 volunteer organizers simultaneously onto every floor of every store in the Woodies chain.

As a result of the arrests, the union has filed a $10 million civil lawsuit against the department store chain and an unfair labor practice complaint with the National Labor Relations Board.

The AFL-CIO union is trying to oust the Independent Union of Woodward & Lothrop, which has represented the chain's workers for 30 years.

The Retail Store Employees Union (RSEU), an affiliate of the clerks union, represents most supermarket workers in Washington as well as employes of the Memco and Korvettes discount stores, but has made few inroads into the Washington department store field.

Woodward & Lothrop is the union's target now because there is only one chance to organize the company every three years, explained Tom McNutt, president of Local 400, which covers the metropolitan Washington area.

Under federal law, one union can petition the NLRB for an election involving employes already represented by another union only during the period from 60 to 90 days before the worker's contract expires. The three-year contract expires June 30, making April the critical month.

If the Retail Store Employees can get 30 percent of Woodward & Lothrop workers to sign cards requesting representation, an election must be held to determine which union will bargain for the workers.

McNutt estimated "almost 2,500" persons have signed union cards, but he said the union is unsure how many names it needs because the chain has refused to give it a list of employes.

Local 400 literature claims that "job by job, wage levels at Memco (which the union represents) run up to $1 an hour more than at Woodies."

Although the fight is between the AFL-CIO union and the independent labor group, Woodies and the Retail Store Employees have squared off against each other.

Woodward & Lothrop Chairman Edwin K. Hoffman yesterday refused to discuss the dispute and said he had instructed his subordinates to do likewise.

In a letter this week addressed "Dear Felow Employee", Hoffman charged the union's "organizers are continually invading our store, which is illegal."

He said the chain's employes "are being harassed by these organizers in many ways" and told employes he would "take every step possible to see that your rights and the rights of the company are not violated."

Union and company versions of the tactics in the organizing drive differ considerably.

While Hoffman refers to union organizers invading, interrupting, and haraxxing Woodward & Lothrop workers, the union says it is the company that is violating the rights of workers.

In a civil lawsuit filed in U.S. District Court last month, the union accused Woodies of denying workers the right to hear the union's message and of depriving union organizers of their right to proselytize.

Dickerson acknowledged that the union sent "at least 150 people" simultaneously into the 14 Woodward & Lothrop stores in January to pass out literature.

On later occasions when union workers returned to the stores, at least 23 of them were arrested, mostly on trespassing charges, Dickerson said.

Union officials say most of the arrests were made in parking lots and suburban shopping malls outside Woodward & Lothrop stores, but admit some of their members were arrested inside the company's stores.

Dickerson said the arrests were made by Woodward & Lothrop security guards, who are hired to arrest shoplifters and have arrest powers granted by local governments.

He said the union workers were handcuffed, photographed and in some instances shained in a back room of a store before being turned over to local authorities. None of the trespassing charges have come to trial and the unionists were released on bail.

Woodward & Lothrop officials acknowledge that "several" union organizers were arrested and say the Retail Store Workers have threatened "to confront us" and disrupt business with their organizing tactics.

Woodies is the most visible symbol of the frustration the AFL-CIO clerks union was met in trying to organize retail workers in the Washington area.

Local 400 has long represented employes of local supermarkets and its contracts with Giant Food and Safeway are reported to pay some of the highest wages in the food industry.

The union said the lowest paid workers at the Memco discount stores earn $4.25 an hour and supermarket checkers start at more than $5 an hour, but wages of beginning workers at Woodward & Lothrop are "near the U.S. $2.90 minimum wage."

The union's efforts to organize the three Washington-based drug chains -- Drug Fair, Dart and Peoples -- have failed. The union lost a representation election at Drug Fair in 1977 and recently made an attempt to organize at Dart Drug.

The union represents employes of the Hahn shoe stores and Releigh's clothing stores, but none of the major general merchandise retailers -- Montgomery Ward, Sears, Hecht or Woolco.

The Retail Store Employees Union will become the biggest union in the American Federation of Labor-Council of Industrial Organizations this summer when it merges with the Amalgamated Meatcutters and Allied Workers of North America.