A federal judge ruled Wednesday that the District has failed to provide special education services to hundreds of eligible preschool-age children and ordered that the city redouble its efforts to find, assess and treat those with special needs.

U.S. District Judge Royce C. Lamberth issued a sweeping series of orders in a 2005 class-action suit (D.L. v. District of Columbia) brought by seven children and their parents, who encountered barriers and delays in securing special education services for which they were eligible under federal law. Lamberth set a series of performance benchmarks for D.C. special education officials and said if they were not met, more stringent intervention would follow, possibly in the form of a court-appointed special master.

Lamberth said Wednesday that District officials’ “persistent failure to live up to their statutory obligations, a failure that works a severe and lasting harm on one of society’s most vulnerable populations — disabled preschool children — is deeply troubling to the court.”

He added that because of officials’ “historic inability to keep their promises to the District’s disabled preschool children, this court hereby makes it crystal clear that failing to abide by the court’s order will earn defendants far more signficant court involvement and oversight than is ordered this day.”

Fred Lewis, a spokesman for D.C. Public Schools, said the District is reviewing the court’s orders and has no comment.

Lamberth’s decision is the latest in a series of federal court decisions finding serious deficiencies in the District’s efforts to meet the needs of disabled students. Special education services to older children, and their transportation, have for years been subject to various forms of court oversight.

About 700 children between the ages of 3 and 5 years currently receive special education services for learning and ­developmental issues, according to Bruce J. Terris, an attorney for the children and their parents. But Terris produced expert testimony showing that significant numbers of D.C. preschoolers who need special education don’t receive it. While the District serves less than 6 percent of the total preschool population — the national average percentage of special-needs children — the analysis presented by the plaintiffs concluded that because of poverty, HIV/AIDs rates and other risk factors, the proportion should be at least 8.5 percent.

Terris said the court decision could double the number of children receiving services.

Lamberth ordered the city to submit biannual and annual reports to the court showing progress in reaching the 8.5 percent level. He also ordered that over the next year the city increase by 25 percent the number or 3- to 5-year-olds referred to special education programs by parents, doctors, social workers or other professionals. Lamberth said the city must ensure that 95 percent of preschool children referred receive a timely evaluation (within 120 days). He also ordered that children from birth to age 3 who are in early-intervention programs receive a smooth and effective transition to preschool special education programs by their third birthdays.

Terris said the District has made strides in recent years, but “still has a long way to go.”

“It’s a wonderful day,” said Margaret Kohn, another attorney for the children and their parents. “Early childhood is the time when you can have the greatest impact.”

Staff writer Del Quentin Wilber contributed to this report.