As nonprofits in Philadelphia are being required by a new law to justify property tax breaks, members of City Council are trying to mitigate some of that pressure.

For the first time, nonprofits must prove that they deserve to be exempt from city property taxes. Councilwoman Jannie Blackwell says her office has been inundated with complaints.

"Churches, I've got churches calling me. Churches were getting ready to march on City Council," Blackwell said Thursday. "I said, 'Please, please don't come. I'll introduce a bill.'"

While Blackwell has a bill that would end the annual reporting requirement, Councilman David Oh introduced a measure to move the deadline to June.

Mark McDonald, a spokesman for Mayor Michael Nutter, said nonprofits own 6,500 city properties. Reports justifying tax exemptions are due at the end of March, but McDonald said an Internal Revenue Service letter certifying a group as a nonprofit is all that's necessary.

Thirty-day extensions are available by request, McDonald said.