Rubalcaba and other opposition leaders have repeatedly called in recent weeks for Rajoy to resign, arguing that the unemployment figures and corruption allegations left him without credibility.
The main corruption scandal affecting Rajoy erupted after the National Court said a former treasurer from Rajoy's Popular Party had amassed an unexplained €22 million in a Swiss bank account. Newspapers reports alleged that for years the treasurer made regular slush-fund payments to top party members, including Rajoy.
Rajoy and his party have denied the allegations but have failed to explain how the former treasurer amassed the money.
On Wednesday, Rajoy complained that the allegations of widespread corruption across the political system were unjust and damaging Spain's image. He called for a cross-party pact to combat the problem and promised stiffer penalties for those found guilty of corruption charges.
He also proposed audits for all political parties, labor unions and publicly financed companies as well as high-ranking officials and possibly deputies and senators.
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