By Dominic Casciani
BBC News community affairs
The Home Office has announced plans to limit the arrival of workers from Bulgaria and Romania - but will they work?
Migrant workers: Restrictions on two new nations
Two years ago, when 10 nations joined the European Union, the UK government was one of the few countries to invite in these eastern workers.
Now the European club is preparing for the entry of two more countries - Romania and Bulgaria.
But Britain is in the grip of self-doubt about a policy that has seen 600,000 workers arrive in little over two years and a complicated, and sometimes vague, feeling that economically and socially it may not be all it has been cracked up to be.
And so, amid pressure to act, Home Secretary John Reid has announced restrictions on Romanian and Bulgarian workers. But with the ink on the rules barely dry, he is already finding it a difficult package to sell.
So what are the restrictions? Any EU citizen can freely seek work in the UK. They have freedom to move, just as Britons do.
Romania and Bulgaria are being treated differently. From 1 January they will have the same freedom of movement. But not all of them will be allowed to seek work.
Low-skilled migrants will only be allowed to seek jobs in agriculture and food processing under a specific scheme with 20,000 places. The government has exercised its right under the EU rules to restrict access for these workers for up to seven years.
As part of the plan, workers from non-EU nations will soon be banned from seeking these same low-paid jobs. This typically means workers from African or Asian nations on borderline minimum wage conditions.
But beyond the headline, it is more complicated. Self-employed Romanians and Bulgarians will not be banned - they can't be because the UK agreed to this in the accession treaty.
Students are also unaffected; if you are a foreigner in education you are allowed to seek part-time work to help pay your way.
What all this adds up to, according to some government critics, is more questions than answers.
Take self-employment for example. There is no legal definition of self-employment - only official guidance. There are many jobs where you can be either employed or self-employed: the building trade, freelancers in a wide variety of fields, electricians and so on.
It is precisely this kind of ambiguity that has regularly seen less scrupulous employment agencies place Eastern European staff in jobs in very dubious circumstances.
The government says it will ensure that those claiming to be self-employed have a genuine skill and reason to be here. But this is a legal grey area which is difficult to police - not least because the government cannot stop Bulgarian and Romanians arriving in the first place.
"Bogus self-employment and cash-in-hand jobs are two of the commonest ways that workers are exploited in the UK," warns Brendan Barber, general secretary of the Trades Union Congress.
"Undercutting legal rights such as the minimum wage drives down wages and conditions for all workers, and leads to tax evasion by both workers and their bosses."
The Home Office also says it is acting to deal with this illegal immigration. Millions of pounds is being poured into immigration enforcement and ministers are pledging action against employers and on-the-spot fines for illegal Romanian or Bulgarian workers. Notably, there is no talk of deporting illegal workers; it's very difficult to deport citizens from one EU member state to another, as the Home Office has discovered during the foreign prisoner releases row.
Some of the most fierce critics of the government see this focus, along with the restrictions on Romania and Bulgaria, as the first serious attempt to "take control" of British borders.
But Habib Rahman of the Joint Council for the Welfare of Immigrants said ministers were trying to have their cake and eat it.
"Restricting legal migration routes risks driving more individuals from the poorer countries to enter irregularly and fuels the evils of people trafficking and smuggling," he said.
"It will also risk the presence of more irregular workers without rights, potentially making it even more difficult for the domestic workforce to secure employment with good wages and conditions."
Official predictions from the two countries claim we won't see a repeat of the phenomenal arrivals of the last two years. Indeed, Romanians and Bulgarians are a tad insulted at the suggestion that they are some kind of threat.
But whether they do turn up at the job centre or not, ministers have recognised they need to be doing more on integration issues.
A great deal of the anxiety about eastern European workers is about how people settle in.
Ministers are pledging action - with the recently created Department for Communities charged with helping local areas learn from each other in how to integrate immigrants.
A small amount of cash is also being earmarked over two years to help schools with little experience of teaching children who speak English as a second language.
Many local authorities view more of this kind of help as crucial. The economy looks after itself, they argue. Many welcome the boost eastern European workers have brought to local coffers. But the practicalities of building cohesive communities can be a lot harder.