Last year, the chairmnan of the Fairfax County Democratic party asked the county registrar who is a Republican, if the county could use a mobile unit to register voters at shopping centers and apartments. She was told that it would be too expensive and besides would need the approval of the Justice Department.

This year, the past chairman of the county's Young Democrats asked the Republican dominated electoral board to allow a registration day at two regional shopping centers. he had gotten approval from the shopping center owners, was assured of additional funding from the county supervisors and saw no problem with the Justice Department, which has jurisdiction over registration practices in the county because Virginia is covered by provisions of the Federal oting Rights Act.

The county electoral board has refused the request. the reason: There is too little time before the last registration day, Oct. 8, to plan for the shopping center voter registration drive.

"They (electoral board members) keep telling me they want to do more to get more voters," said Emilie Miller, chairman of the county's Democratic Party. "Everytime we (Democrats) come up with a plan, we get shot down . . . It really makes me wonder if they're really interested in registering more voters. Are they afraid that the Democrats are more organized and will get out more people to register?"

Mel Rappleyea, the Republican secretary to the electoral board, denies that the latest electoral board action is dictated by partisan considerations. "That's ridiculous," he said. "Doesn't everybody go to shopping centers."

Rappleyea said he and the Republican board chairman, John warner, felt that the use of Springfield Mall and Tysons Corner as voter registration sites "is not proper move to do at this time."

He said not only would the request require the county electoral board to seek additional funding from the county supervisors, but approval of the Justice Department is needed. He said there is not enough time to do those things before the last registration day.

Chuck Kaufman, the past chairman of the Young Democrats who made the shopping center request, disagrees. Kaufman, an aide to county Supervisor Joseph Alexander (D-Lee), said he had persuaded his boss to ask the supervisors to approve the spending needed to provide registrars at the shopping center. It would have cost $450, he estimates.

Alexander said he thinks the supervisors would have approved the money if the electoral board had made the request.

Jack Young, an assistant Virginia attorney general, said the Justice Department has agreed to expedite action on requests to increase voter registration hours.

Fairfax County already provides voter registration at public libraries and certain fire stations in addition to the county registrar's office and the Massey Building in Fairfax City.