They began lining up outside the Prince George's County housing authority office at 9:30 Sunday night, braving the freezing temperatures for a chance to lower their rent.

The first 226 persons in line huddled close together, built a fire in a trash can and patiently wrote their names on a list to secure their chance for more affordable housing.

But at 7 yesterday morning, when the outer doors to the office in Hampton Mall finally opened, almost 900 people pushed through the doors and the result was chaos.

There was shoving and pushing and police had to be called in. Many of the people who had waited all night found themselves far back in the line by the time they got inside the inner office door. And with only 300 Section 8 rent subsidies available on a first-come, first-served basis, that was hard to take.

"I'm so mad and angry," said Deborah March of Forrestville, who have been first in line but ended up somewhere in the hundreds for her trouble. "My feelings are hurt, my head hurts and I'm so depressed I can't go to sleep."

County housing director Earl Morgan said he was not not surprised by the number of people desperate for the certificates. In Prince George's County, he said the problem is not building housing for the poor, but helping them pay for it. There are currently only 1,000 families with the scarce subsidized rent certificates, and the county had not taken any new applications since 1978 until the 300 new certificates became available last fall.

"It is the one program that takes all eligible people, even with zero income," said Morgan. "Public housing can no longer do that. It [Section 8 subsidy] is the program that the welfare recipient can use rather handily," he added.

The lucky holders of the first 300 applications taken and approved will be able to present certificates to private landlords within 90 days, according to Morgan. Their rent will then be held to a maximum of 25 percent of their income with the federal government picking up the rest.

Mary Lou McDonough, the county official in charge of the Section 8 program, said she was sorry about the chaos that cost the first 200 people their place on the list, and gave them a potential wait of up to two years. She blamed the stubborness of the shivering crowd, who refused to back away from the office door, and the police for the orderly queue.

"There was such a mob of people that when we called from the list they couldn't get to the front door," said McDonough. "In other words the police formed a new line. I don't think it was very fair, but we didn't have much choice in dealing with the crowd."

The crowd did not have much choice in dealing with the housing authority; for many of it was their second predawn lineup in as many months.

The county took 1,200 applications for the 300 certificates on Dec. 1, but because the county's advertisement for the certificates broke a Department of Housing and Urban Development rule designed to give equal opportunity to both county residents and those who work in the county, the applications were declared invalid two days later.

HUD ordered the applications be re-taken because the advertisements only mentioned that preference would be given to county residents, according to agency officials. Families who work in the county, they said, were unfairly discouraged from applying.

McDonough tried to negotiate an alternative to the re-taking of the applications for three weeks after her office was notified of what she admitted was an error on the part of her office. Aides to Sen. Paul Sarbanes (D-Md.) also got involved, taking the matter to HUD's central office in Washington.

But HUD lawyers insisted that if they accepted any of the applications they would be open to lawsuits from those who may have been excluded.

But at least one of those who waited in line, Johanna Stefanelli of Laurel, said she might seek court action anyway. She would have been number six on the line, but gave up when the line was discarded for the press of the crowd.

"I been standing here since 11 p.m. last night. I was the ninth person in line and they wouldn't even let me upstairs," she said angirly. "If I find a way, I'm going to sue -- I'm still living with my family."