Nigel Farage: Opening EU migration 'irresponsible'
1 January 2014 Last updated at 10:14 GMT
Temporary restrictions on free movement within the EU of people from Romania and Bulgaria, which joined the EU in 2007, have been lifted.
Bulgarians and Romanians have had the right to visa-free travel to the UK, but the restrictions on the kind of jobs they can take have been dropped in accordance with EU rules.
Nigel Farage, leader of UKIP, said that he thought it was irresponsible to open the door to migration unconditionally.