David Cameron is posturing on the heated issues of migration, job seeking, and benefits tourism within the European Union, according to the EU's most senior employment official, while the acrimonious debate in Britain is based on "myths".

In an interview with the Guardian, the EU commissioner for employment, social affairs and inclusion, Laszlo Andor, said the movement of migrant labour mainly from eastern Europe to richer countries over the past decade was a win-win situation for Britain and deplored the quality of the UK debate, which he said was unlike anywhere else in Europe.

He said: "The National Health Service is a system that would find it very hard to function without foreign doctors. The Olympic sites in London would not have been built without this migrant workforce."

With Cameron demanding changes to the regime of freedom of movement in the EU – one of the single market's four fundamental pillars – in order to curb migration from future new member states, Andor said such discriminatory action would probably prove impossible.

"This is an absurd idea. You create unacceptable lack of freedoms in some countries. The idea is very controversial. What's the rationale behind it? Posturing is the right word in English."

Andor, a Hungarian who studied in Manchester, is to travel to Bristol on Monday to argue his case for the benefits of labour migration within the EU. The commission says that since Britain opened its doors to east European migrants in 2004, the labour mobility has boosted British GDP by 1.2%.

For two years, the commission in Brussels has been requesting evidence from the government to support its rhetoric about Europeans arriving in the UK promptly to claim benefits. All it has received, Andor said, are a few anecdotes.

He accused British politicians of stirring up an uninformed populist furore not based on facts or evidence. In Bristol he is expected to attack politicians who "pander to prejudice or xenophobia".

Andor conceded there were concerns about internal EU labour mobility in other European countries, but said that the nature of the argument in Britain was unique.

"The dimensions are different in the UK because there is a political party [Ukip] that wants to take Britain out of the EU," he said. "There are a lot of illogical associations made that are unfair. It's surrealistic. These are non-existent issues. Benefits tourism as such is a myth."

A number of recent detailed studies support his argument. An analysis from the London-based Centre for European Reform (CER) in October found that the arrival of more than 1 million east Europeans in Britain, mainly Poles and from the Baltic states, since 2004, has had a broadly positive impact on the economy.

"Despite public hostility, the evidence suggests that immigrants from the EU improve the wage prospects of the host population on average, and employers are likely to become more reliant on EU immigrants as the country ages," it found. "EU immigrants are on average younger than Britons; they are more likely to be in employment; and they are overwhelmingly in Britain to work rather than to join a family member. On average, therefore, they are net contributors to Britain's public finances."

EU migrants' participation in the labour market – at 83% – was higher than Britons' participation, while 1.7% of EU migrants were on jobseeker's allowance, half as many as Britons. The study said: "EU immigration is a fiscal benefit. 'Benefit tourism', if it exists at all, is a tiny problem."

A 50-page study from experts at University College London in November reached similar conclusions. "Rather than being a drain on the UK's fiscal system, immigrants arriving since the early 2000s have made substantial net contributions to its public finances, a reality that contrasts starkly with the view often maintained in public debate," it said. "Immigrants are overall less likely than natives to receive state benefits or tax credits. European immigrants have made an overall positive fiscal contribution to the UK."

Cameron's emphasis on curbing freedom of movement rights for new countries joining the EU is seen as particularly specious in Brussels for the simple reason that there is no prospect of any new members for the foreseeable future.

The next country to join, perhaps in a decade, could be Montenegro, for example, a country of 600,000. Andor said: "Would this endanger the labour market stability of a big country?" You must be joking."

Cameron could only push through his limits on freedom of movement by renegotiating the EU treaties with the other 27 governments, a gamble fraught with significant problems for many other countries.

Were he to succeed, other countries would insist on tit-for-tat action. The CER study, for example, points to the estimated 100,000 British expatriate retirees in Spain whose healthcare costs are borne by Madrid if the British have permanent resident status. That could be called into question in any renegotiation.

Andor said: "It's very unfortunate that the political elites allow these problems to grow out of proportion. There has been no influx from Romania and Bulgaria since 1 January. Restrictions are no solution to this."