WASHINGTON  National Republican officials have decided to withhold financial support from all but two closely contested Congressional races in New York, as the party braces for the possibility that it could lose several more House seats in the state.

The decision to abandon much of the state came after internal party polls showed Republican candidates in at least three once-promising races falling behind their Democratic opponents, a party official briefed on the internal deliberations said.

As a result, Republican leaders are diverting money to candidates in other races in which party officials believe they have a greater chance of success, the official said.

The decision by national Republicans to focus on a smaller group of races underscores the degree to which the party is on the defensive not only in New York but also in New Jersey, Connecticut and many other states. The national party is short on cash and is being forced into the difficult position of deciding where to continue to fight  and where to effectively surrender  as the election enters the final days of campaigning.