A GHOST has been spotted in Whitehall.

Indeed, this particular ethereal beast would be hard to miss as it concerns the headline-grabbing immigration and welfare issues. This week, David Cameron announced yet another "get tough" policy; that from January 1 all EU migrants coming to Britain will have to wait three months before they can claim welfare.

The message is clear - do not come to Britain, thinking you can take the system for a ride. By sheer coincidence, of course, January 1 is when the transitional restrictions on Romania and Bulgaria are lifted.

Fears have been raised that thousands of east Europeans will land on British shores in the coming months given what happened after 2004. Then, it was estimated fewer than 20,000 migrants from Poland and seven other EU accession countries would arrive in the UK; last year official figures showed their number was around 670,000.

It was suggested Whitehall had the numbers for how many EU migrants have until now claimed for benefits within the first three months of arriving in the UK but, intriguingly, given it would bolster their argument, ministers had not publicised them.

Instead, No 10 was keen to stress not the numbers but the argument about "fairness".

Yet some statistics do exist. According to the latest available DWP figures, over a year there were 5.7m working age benefit claimants. The vast majority, 5.3m, were UK nationals. Of the rest, the largest number was from Europe, 142,000, then Asia and the Middle East, 128,000, and then Africa, 95,000. But Europe is broken down: the EU, excluding accession countries, was 62,000, the EU accession countries 59,000 and non-EU 21,000. So, the new accession countries represent roughly 1% of all claimants. But what the figures do not show is how many people claimed in the first three months of their arrival.

Yet it has been pointed out EU rules already mean residents of one country are not expected to claim benefits in another for their first three months there.

Jonathan Portes, of the think-tank, the National Institute of Economic and Social Research, suggested the UK Government was bringing in "phantom measures to combat a phantom problem".

A recent EU study said: "The majority of mobile EU citizens move to another member state to work" and so-called benefit tourism is neither "widespread nor systematic".

Facts, of course, should not get in the way of electoral politics.

The Prime Minister's main task is to send a "clear message" to Europe - and more importantly to the hard-working British voter - that the UK is not the soft touch it once was.

Hence, the ghost-like leak from the Home Office about introducing a 75,000 annual cap on EU migration to the UK; illegal, of course, but part of a Tory manifesto kite-flying exercise.

With a poll this week showing 42% of people believing it of "utmost importance" for Mr Cameron to limit immigration from EU countries, the PM undoubtedly thinks raising a Christmas ghost or two will do him no harm at the ballot box.