The District of Columbia government threatened yesterday to stop Metro subway construction unless the proposed midcity Green Line subway is moved from the bottom to the top of the construction list.

The District's surprise move came at a Metro board conference attended by about 130 top Washington area politicians and officials. The meeting was recessed until tomorrow in hopes a compromise can be found.

If the District follows through on its threat, the openings of most subway segments could be delayed for three to four years, Metro construction officials said.

"We don't have a construction program unless this is resolved," Gen. John Egbert, Metro's construction chief, said.

D.C. Mayor Marion Barry, in a speech to the conference tonight, indicated there was room for negotiation. "We're not going to be had," he said. "We're going to give a little and share a little. If you don't want to give, we might not want to share as much."

Without the District's agreement, the federal government cannot award most of $275 million in federal grants.

The 18.86-mile Green Line would serve some of the most disadvantaged sections of the city. It would run through Anacostia, Southwest Washington, 7th, U and 14th streets NW, and Northeast Washington. The line's northern terminus would be at Greenbelt in Prince George's County; its southern terminus at Rosecroft Raceway, also in Prince George's.

Because of D.C. governmental indecision about exactly where the route should go, Metro officials have pushed it to the end of the 101-mile system's construction schedules -- which are negotiated and agreed to by all local governments, including the District. Now, however, the District is stepping up its decision-making process on stations and route alignment. Barry said after the meeting he expects Green Line work to be included in the fiscal 1982 construction schedule. Completion of the entire line is scheduled no sooner than 1990, although a section to Anacostia is scheduled to open in July 1986.

Egbert, Metro Central Manager Richard S. Page and elected officials from the District, Maryland and Virginia met in groups throughout the day to see if they could find a solution and renegotiate a contractually binding construction schedule.

Page wants early action from the District in approving the money because the Carter administration has told Metro it is ready to approve the grants before President-elect Reagan takes office. The money already has been appropriated by Congress.

Although there is no certainty that the new administration would not go along, Page is clearly anxious to take a sure thing and keep the construction program moving.

Contained in the 1981 program are provisions for purchasing 88 new subway cars, which will be needed before any new sections can open, and for construction work on the Orange Line to Vienna, the Anacostia River crossing on the Green Line and lesser projects throughout the system.

The District is willing to free the money right now, Acting D.C. Transportation Director James Clark said, as long as the Metro board agrees "to advance the construction scheduling of the (Green Line) in the District of Columbia to the earliest possible date . . ."

Inevitably, however, that would mean that already agreed-upon construction priorities would have to be pushed back, including the Glenmont line in Montgomery County, the Vienna line, and the Springfield and Franconia line.

Metro's fiscal 1981 contruction program of $323 million includes $189 million in federal money that the District controls. That money was originally part of a massive inner-city interstate freeway program that the District has canceled. Under federal law, if an interstate freeway is canceled, the same amount of money that would have been spent on the freeway can be applied to transit programs.