The Italian prime minister has warned against a fortress mentality in the debate over European immigration, as the Guardian published new data showing tens of thousands of British migrants are claiming unemployment benefits in other EU countries.

Matteo Renzi, the Italian leader who has argued it would be a disaster if Britain left the EU, suggested defensiveness about freedom of movement led to nowhere apart from opening the door to “right-wing xenophobia and nationalism” in Europe.

Renzi made the remarks when asked about his views on EU migration ahead of the publication of a new analysis showing at least 30,000 British nationals are claiming unemployment benefit in other member states.

Speaking just before the terrorist attack in Paris, Renzi told the Guardian, which translated his comments: “The logic of a fortress under siege leads nowhere and in fact, on the contrary, has so far been the key that has opened the door to right-wing xenophobia and nationalism in Europe. We need responsibility, safeguards, controls, collaboration, and rights and obligations – as Europe has always been capable of showing in its best moments.”

The Guardian’s research, based on responses from 23 of the 27 other EU countries, found about 2.5% of Britons in other EU countries are claiming unemployment benefits. This is about the same level as the roughly 65,000 EU nationals claiming jobseeker’s allowance in the UK.

The data reveals that unemployed Britons in Europe are drawing more benefits in nine of the wealthier EU countries than their nationals are claiming in the UK. In Finland, Sweden, Denmark, Belgium, Luxembourg, Germany, Austria, France and Ireland the number of Britons banking unemployment cheques is almost three times as high as the nationals of those countries receiving parallel UK benefits – 23,011 Britons to 8,720 nationals of those nine countries in the UK.

Four times as many Britons obtain unemployment benefits in Germany as Germans do in the UK, while the number of jobless Britons receiving benefits in Ireland exceeds their Irish counterparts in the UK by a rate of five to one.

There are not only far more Britons drawing benefits in these countries than vice versa, but frequently the benefits elsewhere in Europe are much more generous than in the UK. For example, a Briton in France receives more than three times as much as a jobless French person in the UK.

Responding to the research, Downing Street said on Monday that any curbs on EU benefits would be “reciprocal” so changes would apply equally to Brits living in EU countries as EU nationals living in the UK.

“In terms of the changes he is seeking, in terms of welfare reform, he has set out there would be reciprocal changes across the EU,” David Cameron’s official spokesman said. “The prime minister is seeking a number of changes to welfare rules, directly linked to immigration. Clearly those changes would apply across the board.”

Asked whether unemployed Brits could be deported back to the UK from other EU countries under changes to welfare rules, the spokesman said: “The prime minister spoke about understanding clearly the reciprocity of changes across the EU ... He was clear about the EU-wide nature of changes he was seeking.”

The research was published after the German chancellor, Angela Merkel, visited London this month for talks with Cameron, who is campaigning to reform EU freedom of movement. This is part of his drive to rewrite the terms of Britain’s EU membership before putting the issue to a referendum in 2017, if he is still in power.

In November, Cameron demanded curbs on freedom of movement in the EU and new measures discriminating between natives and EU citizens in low-paid work, adding that the UK was getting a raw deal from the EU system of citizenship rights and reciprocal social security arrangements.

The findings highlight a more nuanced and complex picture across Europe than the simplistic version painted by anti-immigration and anti-EU campaigners led by Ukip and elements in the Conservative party. Dr Roxana Barbulescu, researcher on international migration at the University of Sheffield, said the numbers claiming unemployment benefits were minuscule. “Thirty thousand people, or 2.5% of all British nationals, in other EU member states means that the overwhelming majority of Brits abroad as well as European citizens in Britain are not an undue burden for the countries in which they live.”

The data shows an east-west split in the pattern of Britons benefiting from often more generous unemployment payments, as well as a north-south divide. The picture is quite different for the poorer east European countries which have joined the EU over the past decade, with hardly any Britons drawing unemployment benefits in those countries.

The figures for nationals of those 10 east European countries drawing jobseeker’s allowance in the UK remain modest, despite the periodical outcries about “benefits tourism”. There are only about 1,000 Romanians and 500 Bulgarians, for example, drawing jobseeker’s allowance in Britain, according to the Department for Work and Pensions. Of the almost 30,000 Britons on unemployment benefits in other EU countries, only 62 are in the 10 countries that have joined since 2004.

The pattern of Britons being treated generously in Scandinavia and northern Europe goes into reverse around the poorer south, with Italians, Spanish and Portuguese out of work in the UK outnumbering the unemployed Britons in those countries by 13,580 to 5,670.

 But, with the number of Britons in Spain three times that of Spaniards in Britain, and given the demographic differences between these two groups of migrants, the pressure on Spain’s finances is most likely to be on its health service.

Jean-Claude Juncker, the European commission president, told the Guardian in December that Cameron could tinker with British law on social security and migrant rights, but that enshrining discrimination in EU law was a no-go area.

Douglas Alexander, the shadow foreign secretary, will say on Tuesday that Cameron is putting the UK’s place in Europe at risk with his rhetoric about curbing immigration and the potential for a British exit from the EU. On a visit to Paris he will warn that the prime minister’s approach to Europe has seen “the most significant decline in British influence in Europe for a generation”.

British officials concede that the government may have run up against the limits of what it can accomplish with domestic legislation and would need changes at EU level. Merkel has made plain to Cameron what senior diplomats in Brussels describe as her “red lines” – the untouchability of freedom of movement.

“It’s going to be a very, very hard act [for Cameron] to pull off,” said a diplomat. “The Germans have set their red lines. Others are saying: ‘We’re not changing things just to suit [Britain].’”

Mediation of the British issue will fall to Donald Tusk, who chairs EU summits. The former Polish prime minister will be less than keen to agree concessions affecting the many Poles in Britain – at 15,000, the biggest single EU nationality drawing UK jobseeker’s allowance, against just two Britons recorded as receiving Polish unemployment benefit. The task will get harder in 2015 if, as many predict, Jarosław Kaczyński – a chippy, bristling rightwing nationalist –becomes Poland’s prime minister.

Commenting on the Guardian findings, the EU commissioner for justice, consumers and gender equality, Vĕra Jourová, said: “Free movement of people is at the core of having a strong single market and it benefits our economy and society. Abuse weakens free movement. Therefore, member states need to tackle abuse decisively where it happens.”

The data on those receiving unemployment benefit across the EU is just one small snapshot of the immigration and free movement issue. The different countries’ welfare systems vary hugely, complicating efforts at comparison. The payouts offer an approximate equivalent enabling rough comparisons.

According to government figures, there are 2.7 million EU nationals in Britain and 1.3 million UK citizens living elsewhere in the EU.

The Guardian