The revelations come at a delicate moment for Spain, which is beginning to show signs of convincing investors and European authorities that it is serious about reforming the economy and keeping its finances in check to avoid a full bailout like Greece, Portugal, Ireland and Cyprus.
The scandal broke when the National Court reported recently that Barcenas had amassed an unexplained €22 million ($30 million) in Swiss bank accounts several years ago.
Barcenas was the party's long-time treasurer, but resigned in 2009 when his name first appeared in the court's probe into alleged irregular financing practices by the party. His lawyer has denied the Swiss account money was illegally obtained or linked to the party.
The lists published by El Pais said the documents showed that as of 1997, Rajoy received about €25,000 ($34,000) in "envelopes" each year.
"They need to resign for sure and return the money," said Eva Caballero, 52. "They also should be banned from politics and we need a strict ethical code in politics."
Many of the payments occurred during Spain's boom years of the late 1990s when the Popular Party was in power and the construction industry made the country one of the most successful economies in the European Union.
The corruption scandal is the latest to rock Spain, with dozens of other cases involving bankers, politicians, town councilors and even the royal family. But this one has shocked people more, given that Rajoy and his party are demanding enormous sacrifices of Spaniards as the country battles a double-dip recession and 26 percent unemployment.