A fiercely contested plan to turn a crumbling Navy base into a high-tech office park on the Severn River nearly cleared its last major hurdle last night as the Anne Arundel County Council gave its blessing to two of three bills necessary to acquire and redevelop the former David Taylor Research Center.

The votes on the two bills came at the end of an acrimonious all-night meeting of the council. The project's key opponent, Councilwoman Barbara D. Samorajczyk, delayed a vote on the last bill by introducing 23 amendments at midnight - after which the council is barred from voting.

The action by the Annapolis Democrat appeared to be the last obstacle to the county's biggest development project since the opening of sprawling Arundel Mills mall in 2000.

The $250 million project would span 46 acres of prime waterfront land across the river from the Naval Academy, and is expected to generate $3 million a year in new taxes and create jobs for nearly 2,000 workers at gleaming new office buildings, a restaurant and a 100-room inn.

Passage would be a victory for County Executive Janet S. Owens, who has publicized the prospect of new jobs and tax revenue as she runs for re-election, and to Annapolis Partners, developers who have spent more than three years in complex negotiations with the county and Navy. But it would be a setback to residents of leafy neighborhoods around the site, some of whom have worried about traffic jams along narrow streets leading into the complex.

If the last bill passes, work crews would break ground next year and eventually erect 13 planned buildings over the course of the next decade.

The Navy research lab had survived for 96 years, employing a peak of 1,400 workers in the 1980s, before it was closed in 1999 as a result of a congressional mandate to reduce and consolidate military bases across the country.