The figures put out by the Government appeared, at first blush, to indicate that immigrants were engaged in widespread abuse of the benefits system. Yesterday's front-page headline on The Daily Telegraph indicated as much: "370,000 migrants on the dole", it read, going on to suggest that the figures would "reopen the debate over the generosity of the welfare system".
But not everyone agrees with that analysis. Yesterday, a leading economist, Jonathan Portes, director of the National Institute for Economic and Social Research (NIESR), charged that the Government's claims were disproved by its own figures. And his argument bears consideration.
Mr Portes argues that far from proving immigrants are "benefit cheats", the data assembled by the Department of Work and Pensions (DWP) shows that they claim proportionately fewer benefits than those born in the UK. Of claimants definitely identified by the DWP, half are naturalised British, and 98 per cent are entitled to the benefits they are claiming. Only 2 per cent can be shown to be in the country illegally.
But Chris Grayling, the Employment Minister, suggested the figures were a measure of "benefit tourism", telling The Telegraph: "I want to look people in the eye and say that we have a system that's being cleared, that isn't the mess that was left by the previous government, where we can be confident we know the degree of challenge represented by benefit tourism, whether we've got the fraud issue, whether all this is in good shape."
Mr Grayling's figures were assembled jointly with the Home Office, by matching statistics from those applying for a National Insurance number to data on those claiming working age benefits. Benefit claims do not include information on place of birth, but applications for a National Insurance number do, so by matching the two sets of records it is possible to attribute place of birth to claimants.
Statistically, this is a neat trick. But what does it tell us? The DWP statisticians say it does not tell us the number of foreigners claiming benefits. It provides an estimate of the number claiming benefit who, when they entered the labour market, were not British nationals. That may have been years, or decades, ago. Since then more than half, as best as can be determined, have taken British nationality.
The analysis shows that 371,000 people who meet this description were claiming benefit in February 2011, out of 5.5 million claimants. Mr Portes says migrants represent about 13 per cent of UK workers but – from the DWP's own figures – less than 7 per cent of claimants.
The DWP's analysis puts the same point another way. "As of February 2011, 16.6 per cent of working-age UK nationals were claiming a DWP working-age benefit compared to 6.6 per cent of working-age non-UK nationals (at the time they first registered for a National Insurance number)."
It is not surprising that migrants are less likely to claim benefits than nationals. They tend to be younger, have come to Britain to work, and do not qualify for benefits immediately.
Mr Grayling and Damian Green, the Immigration Minister, admit in The Telegraph that "most" of those tracked down by the data-matching exercise have a right to what they receive.
Their accusation is not of fraudulent migrants, but of a system left in "chaos" by Labour. But, their language conveys the impression the UK is being ripped off by migrants with no entitlement to benefits, rather the opposite of what the statistics show. Chris Bryant, Labour shadow Immigration Minister, said the ministers were resorting to "rhetoric and misinformation".
Nigel Hawkes is a contributing editor to Straight Statistics