European Affairs Minister Paolo Savona said on Tuesday that Italy had to be ready for "all eventualities" regarding its membership of the eurozone, which might depend on factors outside its control.
The anti-establishment League/5-Star Movement coalition had nominated Savona to be its first economy minister last month, but President Sergio Mattarella vetoed the appointment because of Savona's scepticism about eurozone membership.
The academic who was eventually named economy minister, Giovanni Tria, has committed Italy to keeping the euro.
"We may find ourselves in a position where it's not we who decide but others," Savona told a panel of senators. "My position regarding a Plan B ... is that we have to be ready for all eventualities."
Italian bond yields initially rose after Savona's remarks and Milan's blue-chip share index erased earlier gains, but then yields returned to their previous levels and stocks partially recovered.
If a new financial crisis should hit, Italy was now "much more vulnerable than we were 10 years ago
"He is a well-known eurosceptic and he seems to be being deliberately provocative," said Chris Scicluna, head of economic research at Daiwa Capital Markets in London.
"To the extent that we knew his views already, the latest comments provide a reminder that there are people in the government with these views and that the Italian government is on a path of confrontation with the European Union," he added.
The governing coalition of the 5-Star Movement and the right-wing League plans sweeping tax cuts and higher welfare spending, which likely will lead the government to renegotiate its budget deficit targets with Brussels.
Bank of Italy Governor Ignazio Visco warned the government on Tuesday to be cautious with public finances to avoid upsetting financial markets and increasing public debt, which is the highest in the euro zone after Greece's.
Visco told a gathering of bankers in Rome that Italy's reform effort had petered out and that, if a new financial crisis should hit, it was now "much more vulnerable than we were 10 years ago".
The governing coalition of the 5-Star Movement and the right-wing League plans sweeping tax cuts and higher welfare spending, but Visco said nervousness on financial markets and Italy's huge public debt argued for a cautious approach.
"Prudence and far-sightedness are needed to avoid (market) tensions and to avoid leaving Italians with a higher debt and lower income in the future," he said.
Italy's public debt, at around 132 per cent of national output, is the highest in the eurozone after Greece's.
Savona, an 81-year-old former university professor, wrote in a book published this year that Italy's entry into the eurozone was a "historic mistake". He has a distinguished academic record and also once worked at the Bank of Italy.
Savona said he would meet with European Central Bank President Mario Draghi later in the day, but gave no further details.