A federal judge sacked a plan by taxi drivers to slowly caravan through the city in protest of proposed new rules, just hours after another judge had given them a green light.

The cabbies' big win dissolved into defeat Tuesday night when U.S. Circuit Judge Dennis G. Jacobs issued an order delaying the demonstration, which was planned for Wednesday.The earlier ruling had cleared the way for a protest of up to 250 cabs, but Jacobs said the city had a right to seek an appeal on whether the demonstration would cripple midtown traffic.

An afternoon rally planned for City Hall was expected to take place as scheduled Wednesday. Norman Siegel, executive director of the New York Civil Liberties Union, which represented the drivers, said the protest drive could still take place, depending on the outcome of possible court hearings.

The judges' rulings Tuesday came in response to a lawsuit filed by an organizations of taxi drivers against Mayor Rudolph Giuliani and Police Commissioner Howard Safir, claiming the drivers' First Amendment rights were violated Thursday when the city barred them from the steps of City Hall. The lawsuit asked the court to force the city to allow the drivers to stage a lawful protest.

Giuliani and the drivers have been at odds since the Taxi and Limousine Commission proposed a 17-point driver reform package that will be voted on by the commission Thursday.

The Giuliani administration wants to impose drug tests on drivers, ban smoking and blaring music, and fine cabbies up to $150 for ignoring or cursing customers.