Britain has a long and proud history of opening its doors to the vulnerable and oppressed; of welcoming workers, students and tourists from across the world. I believe that Britain is a tolerant and welcoming country.

But, right now, we have a big problem with immigration data. UK migration statistics are worryingly inadequate. Between 2001 and 2011, ‘official’ records were off by 350,000.

Without sound evidence it is difficult – if not impossible – to build a full picture of the scale and nature of inward migration to the UK. Policy suffers as a result. How can we plan for the future of schools and hospitals if we don’t know how many people might need to use them? Before we can judge where to spend or invest taxpayers’ money, we need to know where people are living, how long they might live there and whether it’s affordable.

Our current immigration statistics are based on surveys taken by a tiny number of people – as few as 5,000 migrants a year, says the Public Administration Select Committee (PASC) – before taking an informed stab in the dark. Unsurprisingly, these estimates haven’t been accurate. In fact, a report from the PASC concluded that “[m]igration estimates based on the International Passenger Survey are too uncertain for accurate measurement.”

But it gets worse. The EU has now told UK immigration officials to stop asking European migrants how long they’re going to stay in Britain. This is ludicrous. It will make it even harder to measure accurately migration flows. Now we won’t know whether someone is coming here for a week-long holiday, a three-year university degree or for life. And understanding the various categories of immigration is clearly vital if we’re to write effective policy. You don’t need to grasp the minutiae of global migration flows to know that there’s a big difference between someone who’s here for a city break and someone who plans to live in Britain forever.

So, I urge the Government to introduce a system of counting people in and out of the country. This will mean introducing universal exit checks. The e-Borders scheme, which was supposed to do the job, has now fallen by the wayside. In March Sir Charles Montgomery told the Home Affairs committee that the scheme had been “terminated”. This must be replaced as soon as possible. Fortunately, the Home Secretary has already included provisions to introduce exit checks in the Immigration Bill; when introduced, we must make sure these are effective.

The Government should find a way of collecting reliable migration data and resist any measures that prevent us from doing so. With the situation as it is, it is no wonder that the current debate is often confusing and fruitless; full of anger and conflict, and given to descending into shouting matches in which emotive words like ‘racist’ are slung around. Britain and its people deserve better migration data.

Adam Afriyie MP is former Shadow Minister for Science and Innovation. He is current Chairman of POST, although this article reflects his personal views.

Tags: Conservatives, Education, Health, Housing, Immigration, public services