Increased immigration is not linked to rising unemployment in Britain, even during the recent recession, according to a new report.

A report by the National Institute of Economic and Social Research found there was no link between migrant inflows and the overall level of those claiming Jobseeker's Allowance.

The study used National Insurance registrations by foreign nationals for the first time to analyse the impact of immigration on the UK labour market.

The institute's report acknowledged that immigration did have a "modest" impact on the less skilled, suggesting British workers faced more competition from migrants for low-skilled jobs.

"In addition, we tested for whether the impact of migration on claimant unemployment varies according to the state of the economic cycle. We found no evidence of a greater negative impact during periods of low growth or the recent recession," the report said.

The report comes after the pressure group Migration Watch UK said it would be a "remarkable coincidence" if there was no link between a 600,000 rise since May 2004 in the number of Eastern European migrants working in the UK and a 450,000 rise in youth unemployment during the same period.

The group said migrants from the so-called A8 countries which joined the EU almost eight years ago - Poland, the Czech Republic, Hungary, Slovakia, Slovenia, Estonia, Latvia and Lithuania - "tended to be disproportionately young, well-educated, prepared to work for low wages and imbued with a strong work ethic".

But the report said: "We find no association between migrant inflows and claiming unemployment.

"The results show a very small negative and generally insignificant correlation between the migrant inflow rate and the change in the claimant count rate."

The institute said the government had repeatedly associated immigration with unemployment, with ministers warning employers not to rely on foreign nationals to take on roles which could be filled by British workers.

The report supports existing research, which has generally found that immigration has had little or no impact on the average rate of unemployment in the UK.

It also concedes that it is unknown whether a reduction in the number of low-skilled jobs in the UK is being masked by a corresponding increase in the number of more highly-skilled jobs.

The research also differs from a report published earlier in the week by the campaign group Migration Watch, which claimed to find a direct link between increasing youth unemployment and a spike in migration from eastern Europe.

Their report showed that there were 600,000 more workers in Britain in the third quarter of 2011 from Poland and the seven other eastern European countries than there were in 2004 before they joined the European Union. It notes that youth unemployment rose by almost 450,000 over the same period and argues that "it would be a very remarkable coincidence if there was no link at all between the figures".

Sir Andrew Green, of Migration Watch, said "Correlation is not, of course, proof of causation" but that it would be "foolish" to ignore the figures.

Matt Cavanagh, of the Institute for Public Policy Research, said the report was "just conjecture, disingenuously presented as research" and that youth unemployment started increasing before the 2004 arrival of workers from eastern Europe.

"To try to make our youth unemployment problem look like it is only or mainly an immigration problem - as this report does, by selective use of dates, and a methodologically bogus juxtaposition of aggregate A8 migration with aggregate rise in unemployment - is a profound mistake and an irresponsible one at that," Cavanagh told the Guardian.