More than 600,000 unemployed migrants from across the European Union are living in the UK, according to a survey seen by The Sunday Telegraph.

The 291-page report - commissioned by the Brussels commissioner for employment and social inclusion, Laszlo Andor - found there were 611,779 "non-active" EU migrants in the UK last year compared with 431,687 in 2006 - a 42% increase.

The total number of jobless migrants is greater than the population of Glasgow.

While between 2005 and 2006 the growth of non-active EU migrants in the UK stagnated, since 2006 it has been steadily rising, the report said.

The newspaper said the number of people arriving without employment had increased by 73% in the three years to 2011.

It said the figures meant the annual cost to the National Health Service amounted to £1.5bn.

The details emerged as a poll indicated there was strong public support for an early referendum on withdrawing from the European Union.

The opinion poll for the Mail On Sunday found more than half of voters want a referendum on the UK's membership before the next election.

While nearly two-thirds support a vote in the Commons on the issue as early as next month, almost half said they would vote to quit the EU if a poll went ahead in 2014.

Prime Minister David Cameron has pledged to hold a referendum by 2017, but has dismissed the idea of holding it before the next general Election in 2015.

Boris Johnson has said he would like to see a longer waiting time between migrants arriving in the UK and being able to claim benefits.

Speaking to Sky's Dermot Murnaghan, the London mayor said: "We’re aware of the issues that will arise on January 1, 2014, but the UK is still a country and a society that over a long period has benefited from talented people come to work here."