The Home Secretary told The Daily Telegraph that “work is ongoing” to face the  large movements of people in the event of the break-up of the single currency. In addition to fearing a sudden influx of Greeks the U.K. is worried about mass immigration from Portugal, Spain and Ireland, whose economies stand to suffer contagion from a Greek euro exit.  she said the Government was “looking at the trends” on immigration from struggling European economies. She said there was no evidence of increased migration at present, she added that it was “difficult to say how it is going to develop in coming weeks”.

Meanwhile, Home Office data showed that the number of Greeks to obtain a British passport in 2011 rose by 30 percent compared with 2010, climbing from 250 to 325.

High unemployment and political disappointment are driving the Greek workforce to migrate. According to a study published by Fes.de Greece has one of the highest graduate unemployment rates in Europe. High prices along with low salaries which have seen cuts of up to 40 percent since the crisis are forcing young Greeks to consider other countries.

Earlier, David Cameron issued a warning to eurozone leaders that they must put in place proper contingency plans to protect their economies in case Greece drops out of the eurozone.

He said Greek voters effectively faced an in-out choice when they go to the polls in June’s elections amid fears a disorderly exit from the euro could trigger a new global financial crash.