He has been open from the beginning that he would donate $10 million to his own campaign.
The Inquirer first reported April 4 that a portion of that came from a bank line of credit.
"Because this was a contribution and not a loan . . . I [Wolf himself] cannot be paid back any money from the campaign," Wolf said in a statement Thursday. "Frances and I alone are responsible for the repayment of this loan."
Schwartz continued her criticism during a meeting Thursday with the Inquirer Editorial Board before Wolf released details of the loan.
She said that all the campaign contributions in her career had been reported, so anybody can ask questions about who may be trying to influence her - but there is no requirement for a candidate to report details of personal loans.
"What's his relationship with that bank? Who is he indebted to?" Schwartz, a Democrat from Montgomery County, asked during the meeting. "It may be fine. I just want it to be transparent."
Among the assets the Wolfs have put up as collateral are 7.5 million shares of preferred class B stock in the Wolf Organization, as well as 6.2 million shares of common stock, according to a summary supplied by the campaign.
Wolf took out the loan, consolidating debt remaining from a 2011 loan he had taken to supply operating cash to the York County company with $3 million in new debt, in December 2013, the campaign said.
The Wolfs are required to pay back the $4.45 million in 11 quarterly installments of $150,000, beginning in January 2014 and ending in December 2016, the campaign said.
Interest on the loan is a variable annual rate based on 3 percentage points above LIBOR, a commonly used international benchmark for interbank loans. That was calculated at 3.18 percent in the required statement of financial interests Wolf filed with the state March 11.
"If Tom Wolf can't pay back this loan, the bank will control a good chunk of his company," said Mark Bergman, spokesman for the Schwartz campaign. "And the last time the Wolf Organization was indebted to this bank, the majority of the employees lost their jobs. It's clear that Tom Wolf is putting his own personal ambition before his employees."
This was a reference to the point in 2009, during the recession, when the Wolf Organization was unable to keep up with its debts.
It closed its lumberyards, which employed a majority of its workforce. Then, Wolf and two cousins bought back control of the company from the investment bank to which they had sold it in 2006 while intending to retire.
During an hour-long session with the Editorial Board, Schwartz disputed the notion, prevalent in some Democratic political circles, that she would be vulnerable in a statewide general election because of her identification with abortion rights, dating back to her founding of a Philadelphia women's health clinic in the 1970s.
"I think we should stop worrying about that," Schwartz said, adding that support for access to abortion is the majority opinion in the state.
"It's time for us to stop thinking about Pennsylvania as being so behind, because it's not," she said. "Look, President Obama ran ads in Western Pennsylvania on Planned Parenthood. Now he didn't do that because he was a risk-taker. He did it because he knew that Pennsylvanians across the state supported women's access to health services, including abortion."
Besides Wolf and Schwartz, state Treasurer Rob McCord and former state environmental secretary Katie McGinty are running for the Democratic nomination.