More people left the UK last year than in any year since current records began in 1991, statistics show.
Long-term migration into the UK was 574,000, figures suggest
Figures from the Office for National Statistics (ONS) indicate that some 385,000 people left the UK for the long term in the year to mid-2006.
Many of those leaving were "long-term migrants" and not British citizens.
Long-term migration into the UK, meanwhile, was 574,000. The figures show the UK population grew to 60,587,000 - an increase of 349,000.
Of those who left the UK last year, 196,000 were British citizens while 189,000 were "long-term migrants" who had been living in the UK for more than a year.
And according to the Migration Research Unit at University College London, it is the number of non-Britons, or the "turnover population", that has pushed up the figures for those leaving.
"The majority of those are people who came in from Eastern European countries in May 2004 - what we call the A8 countries - and I think what the figures suggest is that, maybe we're now capturing more of those people going home [in the statistics]," Professor John Salt told BBC Radio 4's PM programme.
The latest figures available from the ONS for the most popular places among emigrating Britons show that [from January 2004 to December 2005] Australia was the number one choice.
Those figures - published in April - suggest that, over that two year period, 71,000 British citizens started new lives in Australia compared with 58,000 in Spain and 42,000 in France.
Dean Morgan, of the website workpermit.com, said the bad summer weather had led to a large number of inquiries about emigration.
"Normally in July and August time its quite quiet but this year we've been inundated," he told BBC News.
"Perception of crime is another of the main reasons for people wanting to leave," he said.
"Also, people are worried about their children and they worry about their jobs and their future here and possibly the economy as well."
Australia, New Zealand, Canada and South Africa seemed to be the most popular destinations for emigration, Mr Morgan added.
Meanwhile, the figures also indicated that during the same period, 74,000 people arrived in the UK from the eastern European countries that joined the European Union in 2004, while 16,000 people from those countries left.
However, according to Home Office statistics, around 200,000 people from the same countries registered for work in the UK during that time.
Campaign group Migrationwatch said the figures did not add up.
"This once again highlights that the government has no real grip of immigration or any meaningful idea of the true number coming to and leaving the UK which makes planning for these large population increases extremely difficult," said chairman Sir Andrew Green.
But the Home Office said that while the ONS figures only included those staying in the UK for more than a year, its statistics featured all short-term applications for work, as well as applications from those who may never arrive in the country.
Dr Jan Mokrzycki, of the Federation of Poles in Great Britain, said that although the wage levels were better in the UK than in Poland, the costs of living were also high and many Polish people had realised they were just as well off at home.
"It works out just about even and, of course, there is also a pull on the heart strings for people to go back," he added.
The ONS figures released on Wednesday also revealed that one in four babies born in the UK had a mother or father born overseas.
The proportion of babies born to a foreign parent rose from 20% in 2001 to 25%.
"That reflects the cumulative effect of immigration over the last 40 years," a spokesman for the ONS said.
Overall, the UK saw an increase in births to 734,000 in the year compared with 663,000 four years earlier.
In addition, the figures suggested that the number of people aged 85 or over grew by 6% to 1,243,000 while the number of people of retirement age increased by 1% to 11,344,000.
The largest population growth by district (during 2001-2006) was 14% in Westminster, followed by Camden and South Northamptonshire - both 12%.
The greatest reductions at 2% were in Rushmoor, Middlesbrough, Sefton and Burnley.
The average age was 39 compared with just over 34 in 1971.
The method by which migration statistics are compiled changed in 1991, making some comparisons with earlier figures difficult.