The European Commission complained that the latest Italian budget violates EU budget rules, with government spending and sovereign debt both increasing which would result in the Italian government's inability to reduce public debt in accord with EU regulations.
Tria for his part said Italy and Brussels had "different evaluations" of the situation, but added that he too looked forward to "a constructive dialogue". The increase in the yield premium spilled over elsewhere, with the FTSE-MIB Index of shares extending its losses to tumble 1.9 percent at the close.
Deputy Prime Minister Luigi Di Maio, who heads the Five Star Movement, blamed Brussels for the movement, saying in a video posted on his Facebook page that the spread widened "because the markets think that the government is no longer united".
The letter was issued as European Union leaders gathered for a two-day summit in the Belgian capital which was dominated by Brexit, but where the state of Italy's finances was also on the agenda. "We would therefore ask for your arguments for not taking on board the PBO's opinion", the commission said. He insisted the increase in the structural deficit is less than the European Union calculates.
On Wednesday Conte said he saw no room for changing tack and on Thursday described the budget as "beautiful".
Di Maio and his fellow deputy premier, Matteo Salvini of the anti-immigrant League, are unlikely to back down.
"We are here to solve the problems of the Italians, not bring down the government or let ourselves be intimidated by the ratings agencies, which have made glaring mistakes in the past-and which are wrong again this time", he said.
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Dr Phelps described her victory as a " David and Goliath struggle" and a "great moment for Australian democracy". Preferences from Labor, the Greens and independent Licia Heath are likely to flow overwhelmingly to Phelps.
The budgetary proposal, which is the first for the newly-formed Italian government listed that the budget deficit to about 2.4% of the country's Gross Domestic Product (GDP) which is below the EU's mandated 3% threshold.
In Brussels, Austrian Chancellor Sebastian Kurz showed little tolerance for Rome's profligacy, in a sign of a looming confrontation that could destabilize Italy's economy, the eurozone's third largest. In the EC fear that Italy will increase the record-high external debt, which threatens the stability of the Eurozone.
An escalation is programmed in if Italy opts not to change its spending plans and sticks to its deficit target. He said that the 2.4 percent deficit in and of itself was not the key issue.
The EU commission has the task of checking if budget plans stick to EU rules.
On Thursday, the European Commission warned Italy's government that it was on course for an "unprecedented" deviation from agreed fiscal targets.
He wasn't the only critic, with former Eurogroup chief, Jeroen Dijsselbloem, warning that an Italian budget crisis would lead to an "implosion" within the country's fragile banking sector.