Last week 400 residents of southern Prince George's braved a torrential rainstorm and missed a baseball playoff game to tell Metro officials once again where they want to get off . . . at a future Metro station near Branch Avenue in Suitland.

They turned out again in force this week at the last of two court-ordered public hearings before the Metro board of directors, the latest front in a longstanding subway war that could threaten the future of the line altogether.

For more than two years a coalition of businessmen and civic groups from the Suitland, District Heights and Camp Springs corridor have been fighting a losing battle to persuade the County Council to reverse a decision that shifted the planned Metro route in southern Prince George's from the Suitland area to a more southerly route ending at Rosecroft raceway.

The group went to U.S. District Court in Baltimore last year to force Metro officials and the County Council to abandon the Rosecroft line or pay $1.5 million in damages to persons who say they will be harmed by its construction. The new hearings were one result of that suit.

The pulling and tugging over the route for the subway in southern Prince George's could have an outcome neither side intends -- no subway in the area at all. During the years the dispute has raged, the estimated cost of building either line has almost doubled. No federal funds have been allocated for a southern Prince George's line, and local officials fear a substantial delay caused by the court action could prevent either line from ever being built.

"Right now we're in the worst of all worlds," said Fairfax McCandlish, Metro's public hearing specialist. "We don't have the money, the court case isn't clear and we have to deal with the inflation factor. The longer you wait . . . , the more it's going to cost at the end.

"This is more ammunition for the federal budget people to say: 'Look what we save by not building it,' " McCandlish added. "It's an unfortunate situation."

Both residents and businessmen have high stakes in the controversy.

If the line goes to Rosecroft, 35 houses will be torn down to make way for the subway. Another 54 homes in the predominantly black Hillcrest Heights neighborhood will suffer from noise and vibration as the trains pass, Metro officials acknowledge. Hillcrest Heights residents have vowed to block the line.

The Branch Avenue line, which according to Metro figures would cost $110 million more than the Rosecroft line, would require three houses to be removed and would have significant noise effects on about 24 others.

Small businesses in economic decline along Silver Hill Road near the proposed Suitland Station and the Suitland Federal Center were counting on Metro to bring more federal workers to the area. Car dealer William J. Cairns invested more than $2 million in a new dealership and service center specifically designed with the Branch Avenue station in mind. One development firm, Nicowski and Associates, plans to build a 50-acre industrial park near the intersection of Branch Avenue and the Beltway, and had promised several prospective tenants that Metro service would be available nearby.

Meanwhile along the Rosecroft route, running through a generally less developed area, are several large undeveloped tracts whose value will soar if Metro carries out its plans.

"I don't think there's any doubt about it, both sides stand to make a lot of money," said County Council chairman Parris Glendening, a supporter of the Rosecroft line.

Rosecroft backers, generally outnumbered at the hearings, say that line is necessary to relieve existing traffic bottlenecks along the fast-growing Indian Head Highway corridor, and that the far southern areas of the county would be neglected by the Branch Avenue route.

"We feel the Branch Avenue alignment would completely isolate the people in our part of the county from public transportation while forcing us to pay for it with our tax dollars," said Mike Fischel of the Tantallon South Citizens Association.

Furthermore, Rosecroft supporters say, their line was on the maps first.

As early as 1964 the Prince George's Master Plan showed a rapid transit link running south toward Rosecroft Raceway and neatly bisecting the corridor between Branch Avenue and Indian Head Highway. But in 1968, when Metro approved its Adopted Regional System and Prince Georgians approved an $80 million bonding authority for the subway, the maps showed a line running down the median of Suitland Parkway and ending near Branch Avenue and the Beltway. To the Branch Avenue supporters it was a vote for their line.

"In all the speeches and campaigning there was a map," said state Del. Lorraine Sheehan, who has been in the forefront of Branch Avenue forces. "If you look at the election returns all the people in the Branch Avenue area voted heavily for it. People in that area really feel they were promised something."

But in 1978, prompted by Metro studies of alternative alignments, the Democratic controlled County Council, backed by Democratic county executive Winfield Kelly, decided on Rosecroft. At the time councilman David Hartlove said the Branch Avenue line would cost more and attract fewer riders.

The council's decision prompted charges of secret political dealings, because two large landowners along the Rosecroft route were represented by lawyer Peter O'Malley, a powerful behind-the-scenes figure in county Democratic politics.

O'Malley has consistently rejected those charges. "There isn't any secret, I've been out front," he said. "It's the most logical route to serve a major part of the county -- that's why I think it's right."

Not everyone agrees.

"Rosecroft will enhance the pocketbooks of a few, well established individuals," Thomas Duley, lawyer for Cairns Pontiac and the other plaintiffs in the suit against the Rosecroft line, said this week. "I have no quarrel with making money but I do when it is at public expense."