"Italy knows the rules. They might want to read them again," Vitor Constancio told Spiegel magazine in an interview, according to a pre-release, when asked if the central bank would intervene if needed and rescue Italy from insolvency.
The ECB's never-used emergency bond buying scheme -- known as Outright Monetary Transactions or OMT -- is a potential tool to help Italy but comes with a long list of conditions.
For a country to be eligible for OMT, it must be in a European Financial Stability Facility/European Stability Mechanism adjustment or precautionary programme and support must be warranted from a monetary policy perspective.
A deepening political and constitutional crisis in Italy, the euro zone's third biggest economy, fuelled a sharp rise in the country's short-term borrowing costs on Tuesday and renewed selling in the euro and stocks.
Italy's president set the country on a path to fresh elections on Monday, appointing a former International Monetary Fund official as interim prime minister with the task of planning for snap polls and passing the next budget.
While 10-year Italian bond yields have soared to 3 over percent recent days, they are well below levels they hit at the height of Europe's debt crisis.
They yielded over 6 percent in mid-2012, when ECB President Mario Draghi, a former Italian central bank chief, promised to do "whatever it takes" to preserve the euro.
(Reporting by Michael Nienaber; Editing by Paul Carrel and John Stonestreet)
