IT is a storm that some politicians would be unable to survive. But Mariano Rajoy (pictured above), the Spanish prime minister, and his People's Party (PP) seem determined to bluster their way past the growing weight of evidence that, for a long time, they ran a double accounting system designed to dodge party funding laws and used it to pay senior party members regular cash extras which they may, or may not, have declared to tax authorities. Guilt cannot yet be assumed, but Spaniards deserve a proper explanation. The reaction so far has been of denial and knee-jerk aggression. María Dolores de Cospedal, the party secretary general, is threatening to sue El País, a newspaper, and any other media outlets that repeat the allegations, which are accompanied by copies of handwritten, detailed accounts over a decade in which €7.5m ($10.2m) allegedly went through accounts that were kept hidden from authorities. The party will need deep pockets if it is to carry out the threat, because almost all Spanish media are running with the story. The revelations about the alleged double accounting did not start in El País, which published the documents on January 31st. El Mundo, which is not normally considered anti-PP, had already reported that five former senior officials had confirmed to the paper that the party's top people had taken regular cash-in-hand payments. A former PP deputy, Jorge Trías Sagnier, then confirmed the news. Ms Cospedal claims the accounts are false. But some entries are clearly true. Pío García Escudero, a former senate president, for example, has confirmed that he received a loan of five million peseta to help him repair his home after a terrorist attack. So what about the payments jotted down against Ms Cospedal's name? Or those beside Mr Rajoy's name and those of other party bigwigs? Did they receive the money? Was it in cash? Did they declare it to the tax authorities? And did they know, or suspect, that the money came from apparently secret donations which (at least according to El País) mostly broke party-funding laws?

These questions would be tough enough even if Mr Rajoy, against whose name some €250,000 are marked, according to El País, was not asking ordinary Spaniards to make sacrifices as his government imposes austerity and spending cuts. Ms Cospedal is the regional president of Castilla La Mancha, where the cuts are harshest. As Spaniards brace themselves for yet another year of austerity, recession and growing unemployment, they do not want to see their politicians' noses in the trough.

The PP angrily protests innocence. "I have never received or handed out black money," said Mr Rajoy in a speech on February 2nd. But Spaniards no longer seem to believe the PP is innocent until proven guilty. They want proof. Mr Rajoy's promises of "maximum transparency" will have to be seen to be believed.

The only man the PP happily badmouths is Luis Bárcenas, the former party treasurer, who (according to handwriting experts) wrote the accounts entries. Mr Bárcenas also denies any knowledge of the documents. But court investigators recently discovered a €22m Swiss bank account in his name. And he himself has admitted to having taken advantage of a government tax amnesty last year to pay just 10% tax on €11m that had been hidden away.

When court investigators first began to target Mr Bárcenas, Mr Rajoy claimed the party was the victim of a dark and dangerous conspiracy. Ms Cospedal said exactly the same thing after El País published the latest bunch of documents. That tune is beginning to sound repetitive.