Bill de Blasio on Monday announced that his administration was building and preserving housing affordable to poor and working-class New Yorkers faster than any of the citys previous mayors ever had.

Come Friday, Mayor de Blasios drive to create 200,000 of those units over 10 years may hit a serious speed bump.

On that day, an obscure tax-break program the city has used to create thousands of such apartments is set to expire unless construction unions and real estate developers agree on the wages to be paid on future projects receiving the subsidy.

Jerilyn Perrine, a former city housing commissioner who is now executive director of the nonpartisan research group Citizens Housing and Planning Council, said the expiration of the program would be very troubling.

Read more in The New York Times.