In a major speech on Monday, the prime minister announced that from next year, arrivals from the European Union will be stripped of jobseekers benefits after six months unless they can prove they have been actively looking for a job and stand a "genuine chance" of finding one.
The government is pledging to beef up the "range and depth" of questions in the habitual residence test, which checks that people meet residence requirements for housing and income-related benefits.
However Cameron has been accused of offering empty anti-immigration rhetoric amid fears that Ukip poses a significant electoral threat in 2015.
Sarah Mulley from the Institute of Public Policy Research (IPPR) think-tank said that the UK was "not a soft touch" and that EU migrants are half as likely to claim out of work benefits as British nationals are.
"Migrants in general and European migrants pay more in to the system than they take out, that's largely because they are young people who are working," she told HuffPost UK.
Mulley said that while in theory the British welfare system and NHS was more open to EU migrants than other European systems were, this did not mean it was happening in practise. "The fact is it doesn't happen, at least not in any significant scale," she explained.
Official statistics show that migrants represent about 13% of all workers, but only 7% percent of out-of-work claimants and that migrants from outside the European Economic Area (EEA) represent about 9-10% of all workers, but about 5% of out-of-work claimants.
Gillian Guy, chief executive at national charity Citizens Advice, said while it was important that the welfare system is fair, politicians "must be careful not to encourage myths or misconceptions about who benefits most from the welfare system".
"EU migrants are more likely to be in work and less likely to claim benefits than British residents. Overall, they are net contributors to the economy, putting in much more than they take out. These plain facts must not be obscured by political rhetoric," she said.
And Jonathan Portes, director of the National Institute for Economic and Social Research, also said immigrants were "significantly less likely" to claim benefits than people born in the UK - and that those coming from EU countries put more into the economy than they took out.
He told BBC Radio 4's Today programme that arrivals were mostly younger people whereas the bulk of spending went on healthcare and pensions for older people.
"All the evidence suggests that people who come here from within the European Union make a substantial net contribution to the public finances - they pay in far more than they take out," he said.
He also played down the impact of health tourism as a "minuscule" part of a wider funding issue.
"The problem with people coming from outside the UK in order to sponge off our health service - that may be a problem and we should certainly deal with abuse - but the figures tell us that they impose rather small costs on the health service and certainly, compared to the scale of the problem, it is minuscule," he said.
Cameron said the government had already taken "concrete steps" to bring down immigration and wanted to put in place more restrictions.
"Right now the message through the benefit system is all wrong. It says if you can’t find a job or drop out of work early, the British taxpayer owes you a living for as long as you like no matter how little you have contributed to social security since you arrived," he said.
"My view is simple. Ending the something for nothing culture needs to apply to immigration as well as welfare."
According to the fact-checking website FullFact.org the overall relative generosity of the UK's benefits system in comparison to other EU states can be measured in a number of different ways.
British welfare payments are no more generous than most of Europe when both public and private spending (including private pensions and healthcare) is taken into account.
However UK is at the top of Europe's league table for benefits spending when counting the portion of spending administered by central government.Suggest a correction