The only really surprising thing about the number of migrants claiming benefits in Britain is that the figure is so low. Even more cheering is that a mere 2 per cent of the claims are illegal. Out of 370,000 recipients, fewer than 7,500 are bogus – hardly more than a distant statistical murmur in the context of the 5.5 million people supported by the state. But if the numbers themselves are not shocking, their misrepresentation both by Government ministers and parts of the media most certainly is.

To be clear, the vast majority of the foreign nationals receiving benefits in Britain are wholly within their rights to do so. More than half are people who have since taken citizenship; almost all have come here legally, worked, paid taxes and are now entitled to support. Listen to the Employment Minister, however, and one could be forgiven for concluding otherwise.

Chris Grayling released his newly crunched numbers to the Daily Telegraph accompanied by an opinion piece portentously stressing that he will check every migrant claimant's entitlement. He denies that giving such prominence to so tiny a problem is scaremongering. It is a matter of credibility, the minister says; he must be able to "look people in the eye" and assure them that they can have confidence in the immigration system.

Mr Grayling should be ashamed of such disingenuousness. Of course the Government should apply statistical rigour to immigration and welfare numbers. Of course it should clamp down on benefit fraud of any kind. But to skew reporting of so proportionately negligible a number for a roar of approval from Britain's overdeveloped anti-immigration lobby is as irresponsible as it is inexcusable.

In fact, Mr Grayling's figures wholly debunk the myth of migrants descending on Britain en masse to milk an overgenerous welfare state. But rather than focus on the more pressing question of the millions of British people claiming benefits – legitimately or not – the minister segues straight to efforts to prevent the very "benefits tourism" his researches reveal as a fallacy. After such a display, it is a wonder he can look anyone in the eye at all.

Neither is Mr Grayling the only member of the Government to be taking an objectionable tone on immigration. David Cameron has talked of "discomfort and disjointedness" in local communities, a dog whistle to the Tory right branded by Vince Cable as risking "inflaming extremism". To little avail. Iain Duncan Smith has called for British businesses to hire British workers (a move which, taken literally, would break European law). Meanwhile, Immigration Minister Damian Green talks up plans to slash net migration, causing anxiety to companies that need to fill jobs that Britons are either unwilling or unable to undertake.

More alarming still is the lack of response from the Opposition. Mr Grayling and Mr Green claim that Labour "should be embarrassed" by the mess it made of immigration. Labour should be more embarrassed not to have been on the radio yesterday morning refuting the Government's erroneous spin. Indeed, the Opposition is woefully undecided on the whole subject of immigration. And the Liberal Democrats are little better. Aside from Mr Cable's single broadside, Nick Clegg's party has been almost entirely silent on the subject.

With the economic outlook darkening, and the issue of immigration rising back up the agenda, such reticence cannot continue. Without decent opposition, the unashamedly xenophobic anti-immigration lobby will lead the debate on its own over-simplified terms. It is up to all who would defend Britain as an open society to stand in their way.