Pierre Moscovici, the EU economic affairs commissioner, warned uncertainty over Eurosceptic parties in the Italian poll cast a shadow over the EU project.
Poll leaders the Five Star Movement (M5S) and the Northern League have both called for a referendum on euro membership and spoken out against closer integration.
All the main parties are promising big tax cuts and higher spending and they say they will renegotiate Italy’s fiscal commitments to the EU.
But Antonio Tajani hit out today, saying Mr Moscovici did not speak for Europe and should have been more “prudent” in his comments.
The President said: “He is a French socialist commissioner, he does not speak on behalf of the European Union.
“It’s true that there is concern about lack of stability, but I think there will be a stable government, Italians will go to vote to make this country count more.
“It is true that there are worries in Europe because of instability in Italy, as there have been for Germany until the formation of the government.
“But if I had been in the place of Moscovici, I would have been more prudent.
“I would not have made that statement in the middle of the election campaign.
“The message from the EU is not that of Moscovici. European institutions must not interfere.”
Mr Moscovici said Brussels was keeping a careful eye on the polls and was worried about which way they would go.
He said: “Italy is preparing for elections, the outcome of which is somewhat uncertain.
“What ruling majority will emerge from the vote? What programme? What European commitment?”
And he was not alone with his warnings.
Finnish commissioner for labour Jyrki Katainen said: “I hope that Italy is guided by a stable pro-European government, and that this kind of ideas are supported by the majority of Italians.”
And Former Italian Prime Minister Mario Monti has accused political parties of making “irresponsible” promises ahead of the March 4 election which he said would be a disaster if carried out.
Mr Monti’s government was widely credited with saving Italy from financial collapse during the euro zone debt crisis in 2011.
But he warned: ”This is clearly a country going backwards not forwards
“The spectacle being offered to us and the rest of Europe is one of total irresponsibility.
“It is not just a horrible spectacle that will rebound on Italy in Europe, but it is a huge disinformation campaign that the parties are offering.”
(Additional reporting by Maria Ortega.)