Virginia election laws discriminate against working people by permitting voter registration to be conducted only during regular weekday working hours, gubernatorial candidate Henry E. Howell charged yesterday.

In a suit filed in federal court in Richmond, the self-proclaimed populist candidate for the Democratic nomination for governor charged that the registration hours "constitute invidious and unconstitutional discrimination" against his bid for office.

Howell asked the court to declare Virginia's registration laws invalid and to order that nighttime registration hours be offered immediately in 14 localities, including Fairfax city.

State Attorney General Anthony F. Troy, who is expected to fight the Howell suit in the courts, disputed Howell's contentions in a letter released last month, citing a state study that found "very little connection" between registration hours and registration rates.

Howell, a former lieutenant governor, charged that laws allowing registration books to be open as few as eight hours a week in some localities "resuit in the door being closed (to registration) to over one million Virginians before they go to work and after they . . . return home." Differences in registration hours for rural and urban Virginians deprive residents in rural areas of an equal chance to register to vote. This denies them "the equal protection of the laws guaranteed by the Constitution," he said.

Only Fairfax City in Northern Virginia was named as one of the 14 localities in the state that Howell said will not provide nightime registration opportunities prior to the June 14 primary. "That's bull --," snapped a Fairfax City spokesman when told of Howell's charge.

Fairfax City officials said they are offering registration on Thursday nights from 7 to 9 p.m. and on Saturdays, May 7 and 14, from 9 a.m. to 5 p.m. at the City Hall. all registration for the primary must be concluded by May 14, 30 days before the primary.

In his suit, Howell, a Norfolk lawyer, contented that the disparities in registration hours from jurisdiction to jurisdiction will hurt him more than a Republican nominee for governor since Virginia Republicans choose their candidates in a convention. He contended that he could lose potential votes because of the registration laws, whereas a Republican primary candidate would not be hurt. "A greater percentage of those citizens in Virginia who will vote Democratic are by nature of their employment required to work on a fixed-hour commitment," Howell said.

According to Howell's figures about 45 per cent of the state's workers are employed outside the county in which they live. This makes more obvious the need for nighttime and weekend registration, he said.

Under the Constitution, Howell argued that "a fair, practical, and meaningful opportunity to register is the sine qua non (the equivalent) of the right to vote and cannot be affected by whether or not the affluence or education of the citizen permits him or her to enjoy flexible working hours . . ."

Howell filed the suit on behalf of himself and two residents of rural counties who Howell said are unable to register.

Samuel Justice Jr., a worker at Newport News Shipbuilding and Dry Dock Co. in Newport News cannot leave his job to register at the Isle of Wight county Courthouse before the May 14 deadline, according to the suit. Oneda Pearson, a resident of Dinwiddie County in Southside Virginia, said she, too, is working at the Southside Virginia Training School "at all times" when the county's registration books are open. In Dinwiddie, the books are open Mondays, Wednesdays and Fridays from 9 a.m. to 3 p.m., according to the suit.

Voter registration long has been a volatile political issue in Virginia. The once-dominate Byrd organization was accused of controlling the state through a series of measures like the poll tax and literacy test that effectively disenfranchised large numbers of blacks and poor whites and kept voter turnout relatively light.

Even now, measures designed to add more voters to the state's registration books often fail to pass in the state legislature. Bills that would have directed local registrars to conduct registration in high schools have been killed in the past two sessions of the legislature, though some localities conduct such drives.

The suit is not without its political significance. Howell, who is running against former Virginia Attorney General Andrew P. Miller for the Democratic nomination, tended to downplay his role as a legal activist during his 1973 campaign against Republican Mills E. Godwin. some of his current advisers believe his suit may have been a mistake.

Much of his early prominence in Virginia politics was built on his reputation fighting against the state's political structure in courts and for consumers before the State Corporation Commission. He already is involved in a proceeding before the SCC, which regulates utilities, and his filing of the lawsuit assures him of being involved in a major court case prior to the primary.

In his letter to Howell, Troy, who has represented the state in voting law cases, indicated that state officials are convinced the current procedures, dispite admitted disparities between localities, are constitutional. "I know of no constitutional requirement that a locality with 15,000 must offer the same number of registration days as a locality of 150,000 or 450,000 population," he said.

According to a report furnished by Troy's office, nighttime or Saturday registration is available in the counties of Arlington, Fairfax, Prince William and Loudoun and the cities of Alexandria and Falls Church.