Budge up! Population of England and Wales swells by 400,000 in a YEAR Net migration in England and Wales was 155,000, say Office of National Statistics show Birth-rate between June 2011 and 2012 highest for 40 years Figures show more than 250,000 'internal migrants' fled London The number of people living in England and Wales grew by almost 400,000 in one year - the equivalent of a city larger than Cardiff. Figures released today show the population has continued to rise at the same rate over the past 10 years despite the government's attempts to crack-down on mass immigration. Some 468,900 people moved to England and Wales between June 2011 and 2012, while 313,500 left the country. The number of people living in England and Wales grew by almost 400,000 thanks to continuing high immigration and the highest birth-rate for 40 years In the same period, 729,400 babies were born - the highest birthrate for 40 years. The ONS said: "The number of births was at a 40-year high - the largest since 1972. It should be noted that the two figures are not independent over time, as past immigrants contribute to the number of births and deaths in subsequent years. It means England and Wales has seen the biggest population increase of any other country in the European Union. Only Germany, France and Italy have a larger population than England and Wales in the EU, the ONS said. It has not yet released the figures for the UK as a whole, but the total population is believed to have neared 64million with the latest jump. The latest statistics mean Britain is still on track to reach the landmark population total of 70million by 2027. More than 250,000 Londoners left the capital city, possibly because of the high cost of living The England and Wales population grew by 396,900 thanks to a high birth rate and migration If the UK continues to grow at the projected rate, it will reach almost 100million in a century from now. There are concerns that the ever-growing population will put increased pressure on housing, water and food supplies and the remaining greenfield land in the UK. The number of people living in London shot up by 100,000 to a record high of 8.3million, the figures showed. Although the population is increasing because of international migration, the figures suggest Londoners are fleeing the capital because of high prices. More than 250,000 'internal migrants' left the city, with the majority moving to the east or south east of England. However, more than 176,000 people moved to the capital from abroad. The population has grown steadily since 2002 One figure that may be of concern to businesses in the city is that more than half of those that moved away were aged between 16 and 44. The ONS said: 'Net migration had the biggest impact in the London region with an estimated 52,000 more migrants leaving the region than arriving. In the year ending June 2012, the net outflow for the London region was approximately 10,000 higher than in the previous year. The ONS said: 'The south-east region was the destination for around 40 per cent of the moves out of London and within this figure approximately six out of 10 of these movers were aged between 16 and 44.'