Spain's Prime Minister Mariano Rajoy Saturday denied allegations that he received undeclared payments from his ruling party, as he sought to douse a major corruption scandal.
Rajoy vowed not to resign despite the publication of documents purportedly showing secret payments to him and other top party officials, branding the damaging reports "harassment".
He promised to publish full details of his income and assets, speaking at an emergency meeting of his conservative Popular Party as angry demonstrators outside called for him to step down.
"I have never received nor distributed undeclared money," he said, adding that he would publish online "statements of income, patrimony and any information necessary" to refute the allegations.
"I commit myself personally and all of my party to maximum transparency."
Rajoy, 57, was speaking out for the first time since being named in the scandal which struck at a tense time as the government imposes tough spending cuts on Spaniards suffering in a recession.
Last year he defied speculation that the country would need a financial bailout only for the political scandal to erupt in the new year.
Leading centre-left newspaper El Pais on Thursday published account ledgers purportedly showing that donations were channelled into secret payments to him and other top party officials.
The newspaper said the alleged fund was made up of donations, mostly from construction companies, adding that such payments would be legal as long as they were fully declared to the taxman.
Rajoy said the ledgers were false.
The allegations fuelled anger among Spaniards suffering in a recession that has thrown millions out of work.
"We must not allow Spaniards, of whom we are demanding sacrifice to think that we do not observe the strictest ethical rigour," Rajoy said.
Protesters say ordinary Spaniards are being made to pay for an economic crisis brought on by the collapse of a construction boom which many blame on corrupt politicians and unscrupulous banks.
As Rajoy spoke, demonstrators yelling "Thieves!" gathered near the party headquarters, kept at some distance by police barriers.
Among them, 54-year-old school teacher Maxi Sanchez Pizarro vented his anger at the politicians he blamed for economic hardship.
"My sister is on the verge of being evicted and I didn't get my Christmas bonus, while those ladies and gentlemen not only got their Christmas bonuses but have also been robbing our money," he said.
"They are shameless crooks and thieves," he added. "I hope they have the honour to resign and call an election."
An online petition at change.org calling for Rajoy to resign, launched on Thursday, had gathered nearly 650,000 signatures by Saturday afternoon.
On Thursday El Pais cited ledgers kept by former party treasurer Luis Barcenas, apparently showing payments including 25,200 euros ($34,000) a year to Rajoy between 1997 and 2008.
Barcenas was already under investigation in connection with a separate corruption case, with reports that he had millions of euros in a Swiss bank account.
Rajoy said that case had nothing to do with the party and that it had never had foreign bank accounts.