EU nationals who move to another member state to look for a job are not entitled to social benefits, but they cannot automatically be denied them if they have already worked in the country, an advisor to the EU's top court said this week.
The opinion, which isn't binding until confirmed by the full court, is likely to be closely read in the several EU countries where migrant access to welfare has become politically sensitive.
The issue is at the core of UK debate on EU membership.
The opinion, by advocate general Melchior Wathelet, builds on a judgement in November by the European Court of Justice which said that EU nationals who move to another member state, don't have a job, and aren't seeking one, can be denied benefits.
He said the same applies to people who move to another member states "in order to seek employment there".
Wathelet said the situation is different for people who have already worked in their host state and become unemployed, however.
The case concerns Nazifa Alimanovic and her three children, all of whom were born in Germany.
The family - all Swedish nationals - moved back to Germany in June 2010 after having lived abroad. The mother and the eldest daughter worked in short-term jobs for less than a year and then received unemployment allowances for six months. The younger children received welfare benefits.
The local job centre then decided to stop the payments. German law says that non-nationals, whose residency rights arise solely from looking for work, may not claim benefits.
The European Court of Justice was asked to decide if the decision to stop payments was compatible with EU law.
Wathelet said benefits cannot "automatically be refused" to someone who has stayed longer than three months in a country and who has already worked there.
The person must first be given a chance to demonstrate a "genuine link" with the host country, he added.
In Alimanovic's case this amounted to her having looked for a job "for a reasonable period". The fact she had worked in the past "should also be taken into account", Wathelet noted.
The EU lawyer also noted that, beyond the questions raised by the German court, the children being schooled in Germany gives them and their mother a right of residence.
This means, said the Wathelet opinion, that the local authority could not refuse them social benefits because their right of residence didn't arise solely from looking for a job.
The EU court's November ruling also concerned a case in Germany. That one was about a Romanian national and her son, who were refused certain benefits by a social court in Leipzig, eastern Germany.
The EU court found those who move to another state "solely in order to obtain social assistance" may be excluded from benefits schemes.
"Welfare tourism", as it is often called, has become the subject of virulent debate in the UK, Germany, and the Netherlands in recent years. But there are no conrete figures in circulation to support the arguments.
Speaking in Brussels earlier this month, UK prime minister David Cameron said he wants "widescale change to the rules on welfare and benefit".
This should be part of a reformed EU that Cameron - if re-elected in May - wants to ask British people about in an in/out referendum in 2017.