Updated

Spain's opposition leaders have urged Prime Minister Mariano Rajoy to resign after a newspaper published what it says is evidence that he allegedly received slush-fund payments while serving in a previous government.

A scandal over such alleged secret payments has already shaken Rajoy's party and dented its popularity ratings.

Sunday's El Mundo report contains what it calls further proof that Rajoy knew of illegal financing within his party by jailed former treasurer Luis Barcenas. The paper published what it identified as mobile phone messages between Rajoy and Barcenas.

Spaniards are currently coping with harsh austerity measures and tough economic reforms designed to reduce the country's debt.

The battered economy has been hit by recession and unemployment that has soared to 27.2 percent.