It's unclear what the effect of the move will be. Mayor Michael Bloomberg said on his WOR radio show Friday that the program would go forward anyway.
The Nissan taxis were selected to replace existing cabs as they age and are retired.
More than a dozen wheelchair users joined Liu and other elected officials at a Manhattan news conference.
Edith Prentiss of the Taxis for All Campaign said she wants to be able to stick her hand up and hail a cab just as other New Yorkers do.
Get Eyewitness News Delivered