Spanish Prime Minister Mariano Rajoy on Saturday denied that he and other members of his Popular Party (PP) had received illegal cash payments hidden from tax authorities.

The accusations were "false," Rajoy said at the PP headquarters in Madrid.

"I have never received nor distributed 'black money,'" he said in a speech broadcast on TV.

"I did not come into politics to earn money. I have lost money. I am in politics to change things," he said, implying that he has not considered resigning over the accusations.

"If anyone thinks that I am going to shrink away as a result of this harassment, then I have to say they are wrong," said Rajoy, adding that he would make his tax declarations public over the internet next week.

The prime minister also denied his party had maintained bank accounts in Switzerland and said accusations of illegal payments to various PP members were "infamous."

He made it clear that his party would decide how to defend itself against the attack he said was aimed at destabilizing it.

"This government has a route and is not going to turn from it. I am saying that because we are on the right track. I know that we haven't seen the fruits of that yet, but we will see them, because the seeds have been sown and with a great deal of order," said Rajoy.

Leader of the left-wing Izquierda Unida party Cayo Lara on Saturday asked Rajoy to resign. Head of the Socialist (PSOE) party Alfredo Perez Rubalcaba and the parliamentary spokesperson of the PSOE, Soraya Rodriguez said Rajoy's explanation was insufficient.

The scandal first broke with the discovery of a Swiss account of 22 million euros (30 million U.S. dollars) belonging to former PP Treasurer Luis Barcenas and accusations that he made illegal payments to PP members.