There are growing concerns that the British government is creating a hostile environment for EU citizens living in the UK before Brexit has even materialised.

The European Commission is looking into the issue and gathering further evidence on whether the UK is breaching EU rules by restricting the right of European citizens to move freely around the bloc, Euronews has learned.

“We’ve been very alarmed by the incredible rise in the numbers of EU nationals being detained and then removed or deported. It’s increased exponentially over the last years,” said Celia Clarke, director of the London-based charity Bail for Immigration Detainees (BID UK).

More than 5,300 European citizens were expelled from the UK over the last 12 months, a 20 percent rise from a year ago, according to government data.

Change of tone

The Home Office has said it’s cracking down on criminal offenders and rough sleepers.

But BID UK says many have been deported before they were able to mount a legal challenge.

The charity has shared a letter sent by the UK’s Home Office to a Romanian man telling him he should return to Romania or move to another European country to exercise his fundamental rights and “avoid becoming destitute”.

A spokesperson for the Home Office said the man was a violent offender who was subject to removal.

But BID UK says the tone of the letter alone is worrisome.

“It’s acting as if we’re not a member of the EU, by saying ‘you can go exercise your rights in the EU’. But we are still in the EU,” Clarke said.

Home Office says “description of the letter provided is not one we recognise as a Home Office document” but here it is: pic.twitter.com/JjLau6p1Ir — BID (@BIDdetention) October 30, 2017

Commission on the case

The charity has shared its concerns with the European Commission.

In a written response, the Directorate General for Justice stressed that as long as the UK remains a member of the EU, all rights and treaty obligations continue to apply to it.

The letter, dated Oct. 20 and seen by Euronews, suggested the Commission is keen to gather more evidence of possible breaches of EU rules by the UK.

“We would be grateful for any information you may want to share with us,” it wrote.

A Commission representative confirmed the letter was authentic, adding: “We are aware of an increase in the number of EU nationals who are being detained and facing removal from the UK for immigration reasons. We are looking into this issue.”