Westchester Rep. Nita Lowey’s GOP challenger yesterday demanded that she stop double-dipping and return her $10,000 pension to the state.

“We suggest that Ms. Lowey donate that money back to the state-pension fund until she retires,” said a spokesman for GOP candidate Joe Carvin.

Lowey, one of the wealthiest members of Congress, donates much more than her pension to charity, her campaign said.