UK plans migrant curbs if euro folds - paper | Reuters Theresa May did not say what steps Britain could apply. Every national in the single market has the right to work in a fellow member state, although temporary restrictions can apply to new member countries. "As in every part of government, it is right that we do some contingency planning on this," she told the Daily Telegraph newspaper. "That is work that is ongoing." An increasing perception that Greece or other debt-laden countries might have to leave the 17-country single currency bloc has brought concerns that millions could lose their jobs and be forced abroad in search of work. Although Britain might appear attractive because it is outside the euro zone, it depends on the euro zone for 40 percent of exports, it fell back into recession in the first quarter of this year and unemployment is 8.2 percent. British media have said immigration controls might include temporary visas or worker cards. The Home Office (interior ministry) declined to comment on the newspaper report. A spokesman for the European Commission said it could not comment until it had seen the details of what Britain was saying. Immigration always ranks high among British voters' concerns. It was an issue in the 2010 parliamentary election when May's Conservative Party, which now heads a coalition government with the smaller Liberal Democrats, had promised to reduce net immigration to the tens of thousands, something that it has failed to do. The number of Greek residents in Britain given British citizenship rose 30 percent to 325 from 250 between 2010 and 2011, Home Office figures showed. Britain's Greek population lives mainly in London, numbering between 30,000 and 40,000, the Greek consulate was reported in the Financial Times as saying.