The Italian referendum on the Euro membership

Alright, so the UK had their referendum on the EU membership, which frankly was a long time coming considering it was a notoriously Euroskeptic country.

However an even more significant referendum, especially for the financial world, would be the Italian one on the Euro membership (not the whole EU) and it could easily be as soon as next year.

As things are standing right now, Italy has a Constitutional reform referendum in October, called by the current government, and the first surveys point towards a defeat of the government proposals, confirmed by the recent results in local elections.

Renzi (Italian Prime Minister) has already repeatedly said he'll leave politics if it doesn't pass, which would prompt new elections and, given the unpopularity of his government, we are likely to see a sweeping victory of the protest party M5S (siding against Renzi in the October referendum), whose platform includes an immediate call for the Euro membership referendum and in case of ''Italeave'' it'd be a return of the Italian Lira.

Italy is the 3rd biggest economy of the bloc and its banks are already struggling.

How bad do you think a Euro breakout would be? What kind of impact would it have on markets and the financial sector in general?