With the referendum date for a vote on 'Brexit' confirmed for June, this week has seen a great deal of discussion around UK immigration and the European Union.
Pressure is currently on prime minister David Cameron to release data from HMRC on the number of National Insurance numbers issued to EU migrants, which is reportedly much higher than the number of EU migrants officially declared as arriving in Britain.
Last month's data from the Office for National Statistics (ONS) showed 257,000 EU migrants coming to the UK, but there were 630,000 EU citizens registered for a National Insurance number.
Mr Cameron gave his explanation for the discrepancy in numbers at Prime minister's Question Time, stating that workers can be given a National Insurance number even for a very short-term visit.
He added: “People who are already here but without a national insurance number can apply for them. So these numbers are quite complex.”
The concern has arisen over the fact that requests for information from civil servants have been rejected in the past. Current UK immigration laws are particularly strict on people from outside the EU who have to reply for UK visas, which leaves them subject to strict requirements on minimum income thresholds and background checks.
French President Francois Hollande is among the EU leaders to have vocally discouraged the UK from leaving. Speaking at a summit in Northern France he said: “There will be consequences if the UK is to leave the EU, there will be consequences in many areas, in the single market, in the financial trade, in development, in the economic development between our two countries.
“It doesn't mean that everything will be destroyed, I don't want to give you catastrophic scenarios, but there will be consequences.”
With the option to renegotiate the UK's relations with the European Union on the horizon, discussion looks set to continue about how we can create a fairer immigration system.