The left-wing prime minister warned this week that Europe was at a crossroads and needed to win back people tired of years of economic decline or stagnation.
"Europe cannot simply be a place of codicils, quibbles, parameters, constraints... a no-man's land of bureaucracies," Renzi said earlier this week ahead of a meeting of EU leaders in the Belgian town of Ypres, among World War I's bloodiest battlefields.
"Thousands of young people did not die so that we could wrangle over parameters," he said, adding that the "boring old aunt" Europe has become, "submerged by numbers and without soul", risked missing "a historic chance for change".
The dynamic 39-year-old, who took power in February after ousting his predecessor for failing to boost growth in recession-hit Italy, has a strong mandate in Europe after his centre-left Democratic Party won a resounding victory in the European Parliament elections in May.
But he has warned the electoral fortunes of anti-EU parties in countries such as France, Britain and Denmark, showed a level of anger over austerity which was "much more serious and significant that we can possibly imagine".
Renzi, whose country has a mammoth public debt at more than 135 percent of GDP -- the second largest in the eurozone after Greece -- has joined forces with France in calling for fiscal flexibility in exchange for structural reforms that positively impact growth.
While the former mayor of Florence has promised to "respect the rules" concerning the EU-agreed public deficit ceiling of 3.0 percent, he has also warned the "high priests and prophets of austerity" that "there can be no stability possible if there is no growth".
Youth unemployment, immigration, investment in small- and medium-sized enterprises and tax reform are key issues Italy wants on the table when it dons the EU presidential hat for six months starting July 1.
- 'Change the music' -
Faced with a jobless rate of 12.6 percent at home, Renzi has called for the next European Commission chief -- Jean-Claude Juncker chosen on Friday --to allow more money to be spent on public investment, despite an apparent unwillingness from Germany to change the budget rule-book.
Rome hopes to win support for a large-scale investment programme on energy and telecoms infrastructure, to be financed through so-called project bonds.
"Italy wants the European Investment Bank to play a more dynamic role," Sandro Gozi, Italy's state secretary for European affairs, told AFP.
Citing European research figures, he said there was currently a funding deficit of "around 700 billion euros" ($954 billion) between EU investment and the resources necessary to tackle rampant unemployment and lethargic growth.
"We must change the music. Europe was supposed to be a dream, it has become a nightmare," he added.
Federico Niglia, expert in contemporary history at Rome's Luiss University, said "the Italian presidential semester will begin with numerous difficulties", including "a newly-elected parliament which asserted anti-European forces."
The naming of Juncker as president of the European Commission came after a bitter row over whether the former Luxembourg prime minister would be able to deliver reform -- with Britain leading the "Nay" camp.
"Britain's position will also be a problem for the Italian presidency, because London's ideas on European integration are completely opposed to Rome," which is pushing for greater unity within the 28-nation bloc, Niglia said.
Renzi will also have to persuade the EU's richer countries to the north that bids to ease up fiscal rules will not just lead to renewed public overspending.
For all their differences, the EU's top leaders agree about one thing, Niglia said: "The European election results are an alarm bell impossible to ignore."