A lawsuit filed last week by the Justice Department against the District government and the Techworld development was on behalf of the Interior Department and the Smithsonian Institution. The National Capital Planning Commission is not involved in the suit.

The federal government has just sent a chilling message to the D.C. government, residents of the city and, indeed, the business community here, by filing a lawsuit to reclaim a one-block section of Eighth Street NW.

The government's suit, camouflaged by a pretext of safeguarding historic preservation and the federal interest, has serious implications for home rule in the District. The effect of this gratuitous action by the federal government is to make a mockery of home rule and to create an unhealthy climate for commercial development at a critical stage of revitalization of the old downtown business district.

What other conclusion is there when the federal government -- in an incredible display of pettiness and blatant disregard for the authority of a legally constituted local government -- sues to reclaim part of a street that has been under local jurisdiction for at least a century?

What is it, if not a challenge to home rule, when the Justice Department aids and abets a campaign of harassment and obstructionism to block development of a major commercial project already approved by the D.C. government?

At issue is really whether the District's mayor, city council and zoning commission have authority to approve plans for commercial development in the city. At issue also is whether the federal government has a right to stifle a legitimate business enterprise when there is no threat -- real or perceived -- to U.S. property or to the public welfare.

In late 1983, International Developers Inc., a local development firm, announced plans to build Techworld, a massive mixed-use project that would include a high-technology products trade center, 800-room hotel, conference center, shops, restaurants and underground parking for 2,000 cars. The project, which the developer says will be the largest private real estate development in the District, would occupy a four-acre site on two blocks opposite the D.C. Convention Center.

In the face of bitter opposition from preservationist groups, Giuseppe Cecchi, IDI's president, agreed to make several drastic and costly changes, including a new design for Techworld.

Then, in late 1984, the D.C. government transferred ownership of the right of way along the one-block section of Eighth Street NW, over which IDI plans to build a pedestrian bridge that would connect Techworld's two main components. A year ago, the D.C. Zoning Commission approved construction of the project.

But even as ground was broken for the start of construction last fall, preservationist groups were demanding more changes. They continue to oppose Cecchi's plan to close Eighth Street between Mount Vernon Square and I Street and convert it into a pedestrian plaza. Critics contend the bridge over the plaza would destroy the vista between the Carnegie Library at Mount Vernon Square and the National Portrait Gallery, three blocks to the south. Officials of the Justice and Interior departments not only are supporting this canard but are insisting at this late date that IDI reduce Techworld's height by 20 feet.

Federal bureaucrats are basing the government's claim to a city street in this ludicrous waste of taxpayers' money on an archaic statute that preservationists say was adopted in 1864 in response to complaints about offensive odors from an illegal open-air market being operated in Mount Vernon Square. The smell from the market could not have been as odious as the current suit against the city and Cecchi.

The nuisance factor is made all the more glaring by the fact that Cecchi was close to reaching a compromise with representatives of preservationist groups several weeks ago. With delays costing his firm more than $300,000 a month, Cecchi voluntarily agreed to raise the bottom of the elevated walkway over Eighth Street from 60 feet to 75 feet; narrow the width of the bridge from 90 feet to 45 feet, and open the vista between the Carnegie Library and the portrait gallery from 85 feet to 90 feet.

In addition to creating a public plaza in the block of Eighth Street that would separate the Techworld components, Cecchi volunteered to invest an additional $100 million to landscape the entire three blocks of Eighth Street, from the Carnegie Library to the portrait gallery. Moreover, he agreed to help underwrite a plan, in cooperation with the National Park Service and the University of the District of Columbia, to improve the landscaping and lighting around the Carnegie Library.

Long before making those pledges, Cecchi voluntarily committed to use the District's first-source employment program to hire unemployed D.C. residents at Techworld.

After the convention center, Techworld is the "most important project for economic development of the downtown area," D.C. Mayor Marion Barry remarked shortly after plans for the project were unveiled.

Economic development, free enterprise and home rule will suffer major setbacks if Cecchi is hounded into abandoning Techworld.