Italian bonds and stocks tumbled.
In mid-September they had a heated war of words when Moscovici complained about the spread of "little Mussolinis" across Europe, referring to the rise of right-wing forces across the bloc and Salvini in particular. "It will be the emergence of a Europe of nations, a Europe of respect, a Europe of protection", she said, referring to the EU Parliament vote.
Salvini echoed that view, saying the European Commission - the executive body of the EU - were "enemies of the happiness of Europeans, barricaded in their bunkers in Brussels".
Just recently, the Italian government sent European markets in a frenzy as comments from Claudio Borghi, who heads economic policy for the ruling Lega party, said the country would be better off if it wasn't tied to a single currency, the euro, and operated on its own currency.
Conte emphasized the need to secure the rights of European Union citizens living in the United Kingdom - including 700,000 Italians - when Britain leaves the European Union and Italy's interest in future cooperation on security, according to a statement from the Italian government.
"There will now be a constructive discussion with Europe to show the well-founded reasons for this government's growth strategy", he said. Prime Minister Giuseppe Conte hosted the EU's chief Brexit negotiator Michel Barnier in Rome.
"The EU is built on a lot of promises ... but very few achievements and results (...) quite shabby", she assured.
Mr Salvini, leader of the nationalist League party, attacked the European Commission and its senior figures and pledged to use next year's European elections fight back with a populist "front of freedom".
Rome is due to submit its draft budget by 15 October, which will then be poured over by European Union officials to check whether it abides by their rules.
Italy's expansionary multi-year budget plan published late on Thursday may backfire on the populist government, according to several analysts who see a risk of rising borrowing costs, a bruising battle with Brussels and ratings downgrades.
The standoff is about to culminate as the Italian government will deliver a draft 2019 budget to the European Commission on October 15.