ROME — In what is becoming a dangerous game of chicken for the global economy, Italy’s populist government refused to budge on Tuesday after the European Union for the first time sent back a member state’s proposed budget because it violated the bloc’s fiscal laws and posed unacceptable risks.

The European Commission, the bloc’s administrative body, had repeatedly warned Italy to reduce the deficits in its 2019 draft budget to avoid heavy fines early next year. But Italy’s populist government, which has bristled against Europe’s austerity measures, went ahead and submitted a budget with a proposed deficit equal to 2.4 percent of gross domestic product. That figure was considered much too high for a country whose total government debt equals 131 percent of G.D.P., more than double the eurozone limit.

As expected, the commission rejected the plan, saying that it included irresponsible deficit levels that would “suffocate” Italy, the third-largest economy in the eurozone. Investors fear that the collapse of the Italian economy under its enormous debt could sink the entire eurozone and hasten a global economic crisis unseen since 2008, or worse.

But Italy’s populists are not scared. They have repeatedly compared their budget, fat with unemployment welfare, pension increases and other benefits, to the New Deal measures of Franklin D. Roosevelt that helped America emerge from the Great Depression.