City Council this week could take a significant step toward construction of a new prison in Philadelphia - authorizing the city to purchase land on which one would likely be built.

But the task of approving and financing the prison itself would fall to the next mayor. And on Monday, James F. Kenney, the perceived front-runner in the Democratic primary campaign, said that is not something he is interested in doing.

"We cannot commit to spending hundreds of millions on a new prison when we're not even meeting our obligation to our schools," Kenney said in a statement after coming out against a new prison when asked by a voter on Twitter.

His spokeswoman added that if elected, and if the land was purchased before he took office, Kenney would use it for something else, such as a facility for job training for those reentering the workforce after incarceration.

A new prison, which officials have said could cost from $300 million to $500 million, would replace the House of Corrections in Northeast Philadelphia. The 54-acre property the city is looking to acquire along the Delaware River is just south of the current facility at 8001 State Rd.

City officials say the House of Corrections, built in 1874, is outdated and overcrowded.

As of Monday morning, it was about 275 inmates over its 1,250 capacity, meaning cells for two had to accommodate three, said Commissioner of Prisons Lou Giorla. He said the facility was built when inmates were mostly confined to their cell blocks, leaving insufficient space for programming. He called it "antiquated."

"Nobody wants to build more prisons," Giorla said. "I'm trying to get the message across, we're not building more prisons. We're replacing a structure that's served its time. It needs to be retired."

On Thursday, Council is expected to vote on a bill that would give the city until June 2016 and up to $7.26 million to purchase the land.

Mark McDonald, Nutter's spokesman, said the administration hopes to buy the land by the time the mayor leaves office at year's end. He called the parcel "ideal" for a new prison but said the administration isn't deciding when or whether a prison is built there.

"The next administration doesn't start until January," McDonald said. "It is our intention to provide an array of options for that administration as it looks at its facilities and needs for the future."

Recent polling has shown Kenney far outpacing his nearest competitors - State Sen. Anthony Hardy Williams and former District Attorney Lynne M. Abraham - in Tuesday's Democratic primary. If elected, Kenney could ensure that any talk of a new prison be pushed off for years.

Kenney's spokeswoman, Lauren Hitt, said Kenney does not support building a new prison due to the deficit facing the Philadelphia School District.

Williams, through a spokeswoman, also said he would not support purchasing the land because of the "dire need" facing the city's schools.

Abraham said it was unclear when a new facility will be built but that a new building would provide safer conditions for staff and detainees as well as an "environment more conducive to today's correctional philosophy."

Giorla said the last several prisons built in Philadelphia were done so under court order following two lawsuits alleging poor conditions.

215-854-2730 @TriciaNadolny