On 1 January, Austria, Belgium, France, Germany, Luxembourg, Malta, Netherlands, Spain and the UK will no longer be allowed to bar citizens from the two countries from coming to work.
The seven-year restrictions, imposed from the moment Romanian and Bulgaria joined the EU in 2007, were the longest permitted under EU rules, meant to allow national labour markets a transitional period.
However, in the meantime there has been a rise in anti-immigration parties in several member states, while the EU as a whole has seen record-high unemployment rates.
The economic crisis prompted Spain to reverse its initial decision not to bar workers from the two countries to then restricting Romanian workers.
But the debate about the expiry of the 31 December deadline has been the fiercest in the UK.
Much of the internal discussion has focused on the fact that the previous government underestimated the number of migrants from other EU states after the 2004 round of enlargement.
UK Prime Minister David Cameron, spooked by the rise in popularity of the anti-immigrant Ukip party, has stoked popular fears about benefits tourism: people coming to the UK simply to avail themselves of its welfare system.
Just weeks before the deadline, he announced a series of measures to curb benefits for Bulgarians and Romanians, including a minimum-earning threshold as well as deportation for those found begging.
The government made the move despite admitting that it has no figures on welfare tourism.
It has also led a front at the EU level along with Germany, Austria and the Netherlands calling for a rule change to make it harder for migrants to get benefits.
The European Commission responded by saying none of the four countries has provided any evidence to back up their claims.
Brussels also produced a study showing that the majority of migrants go to other EU countries to work and, on average, use the welfare system less than the nationals of the host country.
Under pressure from the handful of member states, the commission in early December announced some new rules to help prevent cases of welfare tourism.
However, they were denounced as insufficient by both the UK and Germany, where the anti-immigration debate is also picking up.
The CSU party, the Bavarian allies of German Chancellor Angela Merkel, has drawn up a list of proposals to make it more difficult for Romanians and Bulgarians to have access to the welfare system.
Over the weekend it was accused of populist tactics for considering slogans such as “those who cheat are out.”
Politicians in Romania and Bulgaria have called for tolerance in response to the debate.
Romanian Prime Minister Victor Ponta told euronews in early December that Romanians will not invade the UK and that those who wanted to go abroad had already left.
Bulgarian President Rosen Plevneliev asked whether the UK is switching “to isolation, nationalism and short-term political approaches.”
Meanwhile, a recent poll showed that sentiment among the population is more nuanced than the debate at political level.
An Ipsos Mori poll found that 68 percent of Britons would welcome Romanians and Bulgarians if they integrate and work hard.