EU net migration has hit a record high at 184,000, the last immigration figures to be released before the referendum show.
It is an increase of 10,000 on the previous year, according to the Office for National Statistics, and will be seized upon by Brexit campaigners for whom immigration is a key issue.
The figure for the year ending December 2015 means it is joint-highest with the year ending March 2015 – but the highest calendar year on record.
The rise has been driven by a 17,000 increase in the number of people coming to the UK from Romania and Bulgaria in the last year, taking the total from those countries to 52,000.
Citizens from those countries were only allowed to come and work and live in the UK under EU freedom of movement rules from January 2014.
Leave campaigners say that while the UK remains a member of the EU it is impossible for the Government to bring net migration down to the tens of thousands target set by David Cameron.
However, the Prime Minister maintains that under the terms of the renegotiation deal thrashed out in Brussels in February, benefit restrictions for EU citizens will help to stem the flow by making the UK a less attractive place to move to.
But, speaking to Sky News, lead Brexit campaigner Boris Johnson said: “If we want to bring net migration down to the tens of thousands we need a means of doing so. The only means of doing so is to take back control.”
Mr Johnson said: “You see the pressure on public services, you see the waiting lists in hospitals, in GP surgeries and of course in schools.
“People are feeling it and what they resent is the lack of control.”
UKIP leader Nigel Farage said: “Mass immigration is still hopelessly out of control and set to get worse if we remain inside the EU, going on with disastrous open borders.”
EU citizens now account for more than half total net migration – the difference between the number of people arriving and the number of people leaving the UK.
The figures also show that total net migration has hit 333,000 in the year ending December 2015 – the second highest on record and an increase of 20,000 on the previous year.
Immigration minister James Brokenshire said: “Net migration from outside of the EU and within the EU remains too high. These figures underline that there are no quick fixes or simple solutions.
“However, we remain committed to reforms across the whole of Government to bring migration down to sustainable levels, which is in the best interest of our country.”