2013 saw an increase of 42% of Romanians and Bulgarians coming to the UK, with 144,000 workers from the two countries in Britain by the end of last year. Britain's borders opened completely to Romania and Bulgaria on January 1st.
UKIP Director of Communications Patrick O'Flynn said: "There is a clear trend visible here which shows many thousands of Romanians and Bulgarians coming to the UK before border restrictions were lifted on January 1st.
"Such a sharp increase clearly shows that Britain has a considerable pull factor for Romanians and Bulgarians.
"Whilst we do not yet know how many have entered the UK since the government opened the door completely on January 1st, what is clear is that many came here before that date. UKIP's stance is simple: opening the door completely is a stupid and irresponsible risk that we should not be taking. Britain must take back control over its own borders and it can only do that outside of the EU."