* Bulgaria, Romania get full access to EU job market in 2014
* Politicians in EU are worried about Roma and welfare abuse
* Brussels, Bucharest and Sofia say free movement is fundamental
* Rights groups say debate shows underlying prejudice against Roma
BERLIN/BUCHAREST, Dec 15 (Reuters) - Mitko keeps a tidy squat, a tartan blanket on the bed and his clothes stowed away. Lit by candles, heated by a gas canister and padlocked when he is out, it is the 39-year-old Roma's haven inside an old graffiti-covered ice factory in Berlin.
For many European Union politicians, Mitko and his neighbours in the squalid Eisfabrik are a warning of what will happen next year when Romania and Bulgaria get full access to the job market - and welfare systems - of Europe.
Germans, Brits, Danes, Austrians and Dutch are having second thoughts about a second wave of eastward EU enlargement in 2007, which made such poor countries members of the bloc but with a seven-year delay for access to some countries' job markets.
The tone of debate varies. David Cameron in Britain has fulminated against "vast population movements caused by huge disparities in income". One Danish politician has spoken of the need to "stress" Romanian beggars. German mayors have defended free movement in principle but say they are overwhelmed by poor migrants with no jobs and no health cover.
Across Europe the media are railing against "welfare tourism", and politicians, fearing this will boost the far right in May's European Parliament vote, are telling the European Commission to enforce the existing rules more strictly - or change them.
While Britain and Germany might welcome Bulgarian and Romanian professionals to fill staff shortages in hospitals and business, they do not want responsibility for these countries' poor - and especially not for the Roma.
"I don't get any money from the German state," said Dimitar "Mitko" Todorov, waving a cigarette. "If you apply, they just say: 'You don't have a registered address; you don't know the language'."
Leaving behind an ex-wife and three children, he came five years ago to work in construction but injured his back and now earns a few euros a day by begging or odd jobs like shovelling snow in winter. "It's a struggle to survive," said Mitko.
Most Romanians and Bulgarians now in Germany came legally with firm job offers or to study, said Guenter Krings, a senior lawmaker from Chancellor Angela Merkel's conservative party.
But tens of thousands - mostly Roma, he said - already claim welfare under rules making eligible the self-employed, those with children and those who had jobs but lost them. A German court ruling in Essen in October awarding unemployment benefit to a jobless Romanian couple could benefit thousands more claimants.
"We want migration to fill open positions, but I don't see why we also have to open up our social welfare institutions to people who haven't worked a single day in our country," said Krings, a legal expert for the conservatives in parliament.
As the euro zone's biggest and most resilient economy, with a low birthrate and unemployment of just 6.9 percent, Germany is a magnet for migrants. With double-digit percentage rises in net inflows for three years, it received 67,000 Romanians and 29,000 Bulgarians in the first half of 2013 alone.
The government does not know if this will rise dramatically from Jan. 1, 2014. "But there is a fear it will, and we take this fear seriously," said Krings.
In neighbouring Austria, the central bank estimates 5,500 more Romanian and Bulgarian workers will come from next year. A study by a Vienna think-tank estimates it will push up Austria's unemployment rate by just 0.03 percent - but that is enough for far-right politicians opposed to EU integration to complain.
"Austria is not a welfare service or job centre for eastern European countries," said Heinz-Christian Strache, leader of the anti-immigrant Austrian Freedom Party.
"It is a populist debate that doesn't bring honour to Western governments, though their concerns are understandable," said Anneli Ute Gabanyi, a Berlin-based academic from an ethnic German community in the Romanian region of Transylvania.
EU rules set down in 2004 state that citizens who move around should not become "an unreasonable burden on the social assistance system" of their hosts. Brussels cites data showing that "mobile EU citizens" are no more of a burden on welfare than locals and, being younger, are more likely to work.
Laszlo Andor, European Commissioner for employment, says benefit tourism is "neither widespread nor systematic" and represents just 0.7-1.0 percent of the overall EU population.
But it is enough to bait populists such as the right-wing UK Independence Party (UKIP), which in turn elicits a response from mainstream parties. Cameron, seeing the threat from UKIP's anti-immigration stance in May's EU vote and in the British election in 2015, now wants to put limits on free movement and benefits in the EU.
His centre-right allies on the mainland share his concerns and are also lobbying the Commission.
In France, the ruling Socialists worry that workers from low-pay countries undercutting labour costs could boost the far-right National Front in the EU election.
Fears of "Polish plumbers" flooding Europe after enlargement in 2004 contributed to France's vote against an EU constitution a year later, and British and Dutch opinion polls suggest the EU's eastward expansion remains unpopular.
"I don't want acceptance of the European Union to suffer, and I don't want the UKIP in Germany," said Krings, who frets that the euro crisis has already tested the German public's patience.
Romania and Bulgaria are pushing back against attempts to limit the "fundamental EU principle" of free movement. Romanian Prime Minister Victor Ponta vows to tackle abuse by people who "drive their Mercedes to collect benefits"; Bulgaria's Plamen Oresharski is angry at what he calls British "hysteria".
Ute Gabanyi blames an "underlying strain of chauvinism" that is directed at eastern Europeans and especially the Roma, whose population across Europe is estimated at 10 million. Roma rights group Integro in Bulgaria is petitioning the European Parliament against EU politicians who "treat the Roma people as monsters".
"There are only a few Bulgarian Roma who plan to go to Britain after New Year," said Integro's Liliya Makaveeva, adding that despite the tough economic situation in her country, people were not desperate to leave.
But there are persuasive arguments for Romanians and Bulgarians to try their luck in Britain or Germany, which have replaced crisis-hit Spain and Italy as favoured destinations.
Germany will soon introduce a minimum legal wage of 8.50 euros ($11.71) per hour, and Britain's is 6.31 pounds ($10.30) - many times higher than the Romanian rate of 4.74 lei ($1.47) or Bulgaria's 1.85 levs ($1.30).
Romania and Bulgaria pay unemployment, childcare and heating subsidies, but their benefits - and even their minimum guaranteed monthly wages of 800 lei and 310 lev, respectively - are far less than can be earned in state handouts in Britain and Germany.
In Bulgaria, the economy is in such dire shape that Rosen Yordanov, a graphic designer in Sofia with 20 years' experience, is ready to emigrate as soon as the red tape vanishes.
"The situation here has deteriorated a lot in the last four years. I think the market in Britain is well structured and it will give me more opportunities," he said, dismissing hostile noises from Britain's media towards eastern Europe as "normal".
Back in the Eisfabrik, Mitko says he feels no hostility in Berlin, which last year built a monument to the 500,000 Roma and Sinti murdered in the Holocaust, known as "Porajmos" in the Romani language.
EU immigration rules hold little interest for Mitko. What he wants is a nice, clean bathroom to help him integrate into German society, "because it's not very nice when you stink".