On the wall of the antechamber to Mario Monti's office in Palazzo Chigi – otherwise all gilded wood and priceless tapestry – there is a painting of unsettling brutality. It shows a wild boar surrounded by dogs, their bared teeth inches from its snout as they move in for a gory, agonising kill.

If, crossing the room to the latest international financial crisis meeting, Italy's prime minister ever glances at that picture, he must be struck by the aptness of its imagery.

Like the hunted boar, the outwardly unflappable economics professor feels he and the country he leads have been backed into a perilous corner – and unfairly so.

Since he came into office seven months ago, Italy has been a model of good financial conduct. Last Sunday, the University of Toronto published a study of how various G20 countries had complied with the undertakings they made at the Cannes summit last November.

Italy had the second best record (after Britain), Monti told the Guardian. And its performance was the best of any in the eurozone.

Yet ever since March, the rate demanded by investors for buying Italian debt has headed steadily north. It is currently about 6% for a 10-year bond. "There must be something wrong if a country that complies still has such high interest rates," Monti said.

One reason for those rates is that the markets have continued to fret about Italy's ability to repay its mountainous public debt of almost €2tn (£1.6tn).

Another is that the professor's non-party government has found it increasingly difficult to pass structural reforms that would allow the Italian economy to grow. And hours before this interview, there was an ominous flash of sharp teeth from a new direction.

Silvio Berlusconi, whose Freedom People movement has been haemorrhaging support since agreeing to back Monti and his team of "technocrats", told the Wall Street Journal that his party could recover much of its popularity if it withdrew its support – a clear indication that the TV magnate's patience is fraying.

The party he founded still has the wherewithal to bring down the government in parliament.

Small wonder then that at times during our interview Monti seemed close to the limit of his resources. He had returned the night before from the latest G20 meeting in Mexico, where "Europe was, as never before, at the centre of concern and attention", and soon he was due to set off on a visit to the earthquake-stricken city of L'Aquila.

In Rome on Friday he will be hosting a key get-together of the leaders of the four biggest eurozone economies before a summit next week that could decide if the euro lives or dies.

Though he always chooses his words carefully, on this occasion he paused often for long periods and more than once veered down a verbal blind alley.

No deal to save the euro, either on Friday or next week, will be possible without support from Germany. Yet Angela Merkel's room for manoeuvre is restricted by the perception of many of her own voters that they are being asked to bankroll the undisciplined, untrustworthy inhabitants – and governments – of Europe's sunnier lands.

Monti took advantage of the interview to tackle that view head-on.

Just to take as an example the pledges made to the European Financial Stability Facility (EFSF), the bailout fund for states, he said: "We see that, in percentages, Germany covers 29.1%, France 21.8% and Italy 19.2%."

Loans from Italy to support Greece, Ireland and Portugal amounted to €31.5bn – a fifth of the total.

"Italy has not until now asked for loans," he said. "She has made a lot of them and every day that passes, it is in fact subsidising others with the high interest rates she pays in the market."

As for discipline, the EU expected Italy to have a budget deficit this year of 2% of GDP while supposedly "ultra-virtuous" Holland was heading for a 4.4% shortfall.

Nor was that the only irony. The eurozone overall had a combined budget deficit and public debt "that, as a proportion of GDP, is lower than that of the UK, the US and Japan".

Referring to Britain, Monti said he saw Italy's role as that of a bridge between what he termed the "ins" of the eurozone and what he perhaps optimistically described as the "pre-ins" – the European countries that have not yet joined.

In a rare if not unprecedented admission by a prominent European leader, Monti said: "It could be that from a short-term economic standpoint, the decision not to belong to the euro has given [Britain] some advantage."

But, implicitly contradicting David Cameron's assertions that the UK could still have an impact on Europe's future, he added: "The influence of the UK in determining the overall direction of European politics has weakened."

• The Guardian's interview with Mario Monti was conducted in partnership with correspondents from Gazeta Wyborcza of Poland, Le Monde of France, El País of Spain, La Stampa of Italy and Süddeutsche Zeitung of Germany.