Popular Party (PP) Deputy Prime Minister Soraya Sáenz de Santamaría on Friday came out in defense of the government in the wake of the Bárcenas financing revelations and made assurances that “if we have to toughen measures, we will do so.”

“This government is stable,” she continued. “Firstly because its parliamentary majority is, and secondly because it does what needs to be done.” Over the suggestion that the prime minister had received cash payments on the side, his deputy said: “I have never seen him break a rule. While in government, in opposition, and then in government again, I have always seen in Mariano Rajoy an exemplary conduct, an example of an upright life and one dedicated to public service.”

Rajoy is due to appear at an emergency meeting of the PP’s Executive Committee on Saturday. There he will face the inquisition of leading party figures.

José Antonio Monago, Alberto Núñez Feijóo and Juan Vicente Herrera, regional PP premiers of Extremadura, Galicia and Castilla y León respectively, have called for an internal audit and public explanations to be given greater urgency in the face of the outcry over the matter.

“There must be maximum transparency at this time and [Rajoy] needs to give all the necessary explanations,” said Monago.

Herrera added that the extracts from Bárcenas’ ledgers published by EL PAÍS were not without basis and should be investigated by the courts. “There’s no point in shooting the messenger.”

Former PP Prime Minister José María Aznar on Friday filed a lawsuit in a Madrid court against EL PAÍS for defamation in response to suggestions that he too was paid salary top-ups from a slush fund.