EXPERTS have claimed that official EU migration numbers have been “systematically” under-estimated after the Office for National Statistics (ONS) downgraded to “experimental” the status of its quarterly figures, due out today.

The ONS said it under-estimated levels of EU migration to the UK, affecting figures on the number of migrants from EU8 countries – like Poland – since 2016. It added that migration from non-EU countries had been over-stated.

In a statement yesterday it said: “In the year ending March 2016 – the latest point at which we have adjusted data available – EU net migration is around 16% higher than our published estimate ... net migration is around 13% lower than our published estimate.”

Experts at the University of Oxford’s Migration Observatory said the latest ONS analysis showed official data has been “systematically under-estimating net migration from EU countries”.

Its director, Madeleine Sumption, said: “We have been pointing out for a while that something wasn’t quite right in the net migration statistics, and that the comparison of EU versus non-EU net migration did not seem plausible.

“This matters because, for the past nine years, the UK policy debate has been fixated on a single data source, which couldn’t bear the load that it was forced to carry.

“Whether the question is how to meet the net migration target or what to do about international students, the truth is that the data were simply not robust enough to be picked apart in such detail.”

The news came as Scotland’s Immigration Minister, Ben Macpherson, told The National about the worry felt by EU nationals living and working in Scotland about what would happen to them post-Brexit. He has been meeting employers and staff around the Highlands and Islands, stressing the Stay in Scotland campaign that aims to deliver the message from the Scottish Government, and Scotland as a whole: “We want people to stay and we want to support people to stay.”

To help do that, he said a free helpline – on 0800 916 9847 – was now available to offer help and advice only in Scotland.

“Among the EU citizens I’ve spoken to there is, as there has been since the Brexit vote, an understandable sense of concern and you can understand that people are worried,” said Macpherson.

“But one thing that has actually been reassuring is the amount of EU citizens I’ve spoken to that are saying they are concerned about what the UK Government are doing, are concerned about the situation but they feel very welcome in Scotland.

“That message, not just from the Scottish Government but from Scottish society as a whole has made a difference.”

He said there were also fears over freedom of movement, should Home Secretary Priti Patel decide to stop it on October 31 if there is No Deal on Brexit.

The minister said he was concerned about the lack of proper legal protections for EU citizens, and added: “The 3 million [charity] have rightly raised awareness of the challenges around the high risk of potential discrimination between those who had settled status and those who had been here and hadn’t obtained settled status, and those who are just arriving.

“Scotland has benefited hugely from freedom of movement with people coming here, working in our economy, supporting our public services and crucially enriching out communities collectively.”