The D.C. housing department, in its most concerted effort in 12 years to collect millions of dollars in outstanding rents, has warned 3,777 public housing tenants that they could be evicted unless they take steps by Monday to straighten out their accounts.

The notices, mailed to heads of households in 25 percent of the city's 12,000 public housing units, come about a week after the General Accounting Office criticized the department for failing to fulfill promises made three years ago to improve the city's rent collection system. City officials said yesterday, however, that the action had been planned before the release of the report.

Yesterday afternoon Neighborhood Legal Services, whose lawyers often represent public housing tenants in disputes with the city government, asked Mayor Marion Barry to rescind the notices.

"The notices are outrageous in that scare tactics are being used by the government against a large group of very low-income people to coerce them into submitting payments," NLS officials said in a letter to Barry.

NLS officials contended that the city's rental records were "notoriously inaccurate" and that the notices "may coerce tenants into paying amounts not owed for fear of losing their homes."

They also criticized the notices for not pointing out that tenants can withhold rent if the city had failed to make needed repairs.

Public housing administrator Sidney Glee said yesterday, "This is not a scare tactic. We intend to collect our money; there is no question about that . . . We can't keep letting people flout their responsibilities."

Glee acknowledged that the records were in poor shape, as pointed out in the GAO report released last week. He said the purpose of the notices was to determine how much tenants owed the city.

"This is a standard way to verify rent," said Glee.

The notices begin by informing the recipient, "An examination of your account indicates that it is seriously delinquent" and ends with a warning in capital letters that "failure to make an appointment by June 7, l982 to correct or pay this delinquency may result in eviction proceedings against you."

The second half of the notice gives the amount allegedly owed by the tenant. Glee said if tenants could produce canceled checks, money order receipts or other documents as proof of payment, the record would be adjusted.

Tenants lacking proof of payments would be required to pay again, Glee said. Tenants will be asked to sign an agreement to pay off the arrears in installments.

Glee said any tenants owing back rent who have not reached their managers by Monday will receive notices telling them they can be evicted within 30 days if they make no arrangements to pay. If there is still no action, the city will go to court to evict the tenant, Glee said.

The District government, the city's largest landlord, owns and manages 53 public housing projects. Its more than 50,000 tenants, most of them elderly women or single mothers with children on public assistance, are among the city's poorest residents.

For years, the city has had a running battle with tenants over rent collection. While some tenants do refuse to pay rent for no valid reason, others go to court and win the right to withhold rent until the city makes needed repairs.

These court battles have evolved into a vicious cycle, in which the city defers making the small repairs tenants request because it doesn't have the money. Many tenants refuse to pay unless repairs are made. The city, meanwhile, falls further behind in its repair schedule because it has not collected all the rent money due.

Twelve years ago, the city sent out thousands of notices for delinquent rents and subsequently attempted to evict those who did not pay. A rent strike resulted that went unresolved for three years. The current total of uncollected public housing rents is estimated at $3 million.