The Federal Emergency Management Agency has slammed the brakes on the project for at least three months - saying it's unclear whether the $29.6 million construction job is a wise use of Sept. 11 relief funds. FEMA says it won't bankroll the project unless the Port Authority - which runs the rail line between New Jersey and Manhattan - spends more time on studies and involves the public, The Post has learned. "There's a limited amount of funding, and we want to make sure it's all well spent," said Brad Gair, FEMA's top official in New York for 9/11 relief.

FEMA listened to protests by West Village residents and businesspeople who said the PA was railroading a "boondoggle" that will hurt the neighborhood. FEMA now wants more information on the construction's impact on the neighborhood's brownstones, cafes, boutiques and the Stonewall Historic District, the only national landmark honoring gays and lesbians.

Opponents of the project are elated by FEMA's stance. "That $30 million should be used to rebuild New York, not further destroy it," said West Village resident David Ryan. The neighborhood protests have also caught the attention of FEMA's inspector general's office, which looks into waste and abuse of federal funds. In a letter to the PA, Gair said the agency must fully comply with federal environmental and historic-preservation laws. That could take at least three or four months and should include public review and comment, he said. The PA had hoped to break ground this month.

Use of the West Village PATH stops has doubled since 9/11, when the World Trade Center station was destroyed. But Gair said that by the time the new exits are built, it could be less than six months before the projected opening of a new WTC station in December 2003. That's not a "reasonable benefit to displaced commuters," he said.

The PA insists second exits at the West Village stops are still needed to evacuate riders more quickly in case of a fire or another terrorist attack. "We still think it's a safety issue," said PA spokesman Steve Coleman. He said the agency will use its own capital-improvement funds if FEMA doesn't hand over the money.

Opponents say a solution already exists: The PA should run express trains to the next stop north, at 14th Street, which has double platforms and quick connections to subway lines going in several directions. At Christopher Street and West Ninth Street, commuters must climb long stairwells to the street, then walk three blocks to a subway.