Italy’s Prime Minister Matteo Renzi, facing a key referendum at home later this year, accused Germany, France and Spain of breaking European Union rules on deficit control and spending in an interview with Corriere della Sera. Nations “will have to justify themselves for failing to respect the rules,” he told the Italian newspaper. “The size of Spain’s deficit is twice ours, France does not even respect the Maastricht Treaty—having a deficit still over 3 percent of GDP—Germany breaks the trade surplus rule.” Renzi spoke out against fellow EU leaders after attending a summit in the Slovakian capital Bratislava on Friday. The gathering was a “wasted opportunity” and didn’t address the key economic challenges facing Europe after the U.K.’s vote to leave the bloc, he said in the interview. He called on EU leaders to acknowledge that austerity policies have failed. Renzi said he refused to join a news conference with German Chancellor Angela Merkel and French President Francois Hollande after the meeting. Talking to Corriere, he denied that his criticism was aimed at fostering support among Italian euro-skeptic voters before a key vote on constitutional reform expected in November or December. “I have never been more optimistic than now” about the outcome of the referendum, he told the newspaper. Renzi has previously insisted the constitutional reforms would simplify the legislative process and boost political stability in Italy, and has said he’ll quit if voters don’t approve the changes. A poll published by newspaper La Stampa on Sept. 4 gave the No vote 51 percent against 49 percent in favor. A previous poll in May had Yes at 56 percent. Last month the government asked that the EU afford Italy the necessary “flexibility” to budget for reconstruction in the regions hit by a devastating earthquake. Renzi told Corriere that Italy will abide by the EU’s “exceptional-event” clause and exclude from its deficit calculation all costs related to reconstruction as well as to the flow of migrants. The government won’t negotiate with the EU over Italy’s budget law, which will extend its efforts to bring the deficit within a limit of 3 percent of gross domestic product, Renzi said in the interview. The premier also criticized an EU document on migration agreed on at the Bratislava meeting, saying that the summit failed to address the issue. Renzi will be in New York on Monday and Tuesday and will speak to the United Nations General Assembly.