As if immigration wasn’t a touchy subject already in the UK (for what it is worth, I tend to think that the vote Brexit was not just about a desire to cut down on immigration, but a broader desire to control everything from London as opposed to Brussels or Berlin), a new report has been released which accuses the official government figures of fudging things.

MigrationWatch, a think-tank chaired by Lord Green of Deddington, claims that the 15 years between 2001 and 2016 saw 6.6 million people added to the UK’s population and that 82 percent (5.4 million people) of that increase was due to migration. That is, if migration had been zero, then the population increase of the UK over that time would have been only 800,000. The 2016 UK population was 65.7 million people, meaning that the population had expanded by more than 10 percent since the turn of the century.

The Office of National Statistics (ONS) claims that less than half (3.1 million) of the population increase in the 21st Century was due to migration.

So what accounts for the difference between the two figures?

MigrationWatch argues that the population growth attributable to migration should count not only those that have come to the UK’s shores, but also the children of those first-generation migrants. And when you add those children (2.3 million) then you get the full picture of the effect of the expansive migration allowed under the Labour and Conservative governments since 2001. According to Lord Green, this paper and the figures it produced “shone a light on this elephant in the room”. He added that “The Government have been remarkably coy about the true impact of immigration on our public services. It is almost as if officialdom preferred to avoid the issue as far as they possibly can.”

Critics of mass migration to the UK, including MigrationWatch, argue that public services have come under increasing pressure and strain due to unprecedented population growth and that wages also fell. MigrationWatch argues that immigration must be reduced and that current largescale migration is “rapidly changing the size and nature of our society”. The latest figures released by the ONS will not fill MigrationWatch with joy either: even taking the ONS’s definition of migrants (and not migrants’ children) the population rise between 2016 and 2017 was nearly 400,000 people and 59 percent of that was due to migration (a higher proportion than that counted by ONS in the period 2001-2016).

Now, in ONS’s defence, internationally recognised definitions do not count the children of first generation migrants, born in the country that their parents migrated to, as migrants. And this makes sense. The children were born in the UK; they weren’t migrants to the UK. So it is easy to dismiss the MigrationWatch report as inaccurate, “fake news” and dismiss it as a cheap attempt to get points to push their particular barrow. But if the report’s aim is to get people talking about migration and to make them aware of the rapid escalation in population that can occur through migration (especially if those migrants prove to be particularly fertile) then there is something to be said in its claims that the ONS’s official figures do not fullt capture the full extent of the population explosion in the UK due to migration.

It will be fascinating to see if Brexit (in whatever shape it actually occurs) has any effect on these figures and whether migration will come down once the country gets control over its borders again. Prime Minister David Cameron once promised that his government would get net migration down to the “tens of thousands” a year. At the moment, the latest figures are a long way off that.