Spain’s gross domestic product shrank by 0.3 percent in the quarter, National Statistics Institute data showed, meaning the eurozone’s third-largest economy has been shrinking for 15 months.

Over the year, economic output slumped 1.6 percent, said the data, which confirmed earlier estimates.

The persistent recession and mounting outcry over budget cuts underscore deep divisions over policies that require debt-stricken eurozone states to slash spending to repair their finances even in recession.

The International Monetary Fund admitted last month that it had underestimated the extent to which painful austerity measures brake economic growth.

Much of the eurozone is in recession and suffering from towering unemployment rates.

In Spain, crippled by a 2008 property market crash, the government is tipping an economic slump of 1.5 percent this year.

Its forecast of a 0.5-percent contraction in 2013 is widely viewed as highly optimistic, with the European Commission, for example, saying it expects output to tumble 1.4 percent.

Miserable economic activity has left Spain with an unemployment rate of 25 percent, topped only in the eurozone by Greece with a jobless ratio of 25.1 percent, the highest in the industrialized world.

Scarce jobs, sharp tax rises, and severe public spending cuts including in health care and education prompted general strikes in Portugal and Spain and stoppages in Greece and Italy on Wednesday.

General strikes in Spain — where unions claimed many millions abided by the action — and Portugal, paralysed swathes of industries and hit road, rail and air transport.

It was the broadest coordinated European industrial action since the crisis broke out, unions said.

Hundreds of thousands of protesters flooded Madrid, chanting, blowing whistles and setting off firecrackers at the spearhead of the Europe-wide action, which boiled over into sporadic violence.

Spanish youths burned bins in central Madrid, shattered the windows of a KFC fast-food store, and hurled bottles and stones at police, who responded with rubber bullets and baton charges. In the northeastern city of Barcelona, youths set a police van ablaze.

Portuguese police struck protesters with batons after coming under a hail of stones and rubbish from them.

In Italy, about 20 activists were seen beating an officer with sticks and baseball bats in Turin and a dozen officers were hurt in running street battles in Milan.

In Rome, dozens of young protesters hurled stones and bottles and smashed up cars as they tried to break through lines of police who responded with tear gas and used armoured cars to force them back.