A sharp fall in net immigration was due largely to a drop in the number of students entering the UK, despite David Cameron’s pledge that the Government wants to attract the brightest and best young people from overseas.

Figures published today revealed that a net flow of 163,000 migrants came to Britain in the year to June 2012, down from 247,000 in the previous 12 months. The number of people coming in fell from 589,000 to 515,000, while the number leaving the country rose from 342,000 to 352,000. On a visit to India last week, Mr Cameron insisted there was no limit to the number of students from the country who would be allowed into Britain, as he answered criticism that bureaucratic visa rules are deterring young people and businessmen. But the Office for National Statistics (ONS) figures showed that some 197,000 foreign students arrived in the 12-month period, down 42,000 (17 per cent) from 239,000 in the previous year, while the number of visas issued for study – 209,804 – was 20 per cent lower.

The ONS said there was a “significant” decrease in the number of immigrants arriving from New Commonwealth countries, which include India, Pakistan, Bangladesh, Botswana, Kenya and Malawi. Some 117,000 immigrants from these nations arrived in the UK in the year to June, down 51,000 (30 per cent) from 168,000 in the previous year.

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A total of 62,000 immigrants arrived from countries which joined the European Union in 2004, including Poland, the Czech Republic and Lithuania, down 24,000 (27 per cent) on the previous year.

Mark Harper, the Immigration minister, said: “Our tough reforms are having an impact in all the right places – we have tightened the routes where abuse was rife and overall numbers are down as a result.” He insisted that sponsored student visa applications for the UK’s world-class universities were up, and the number of skilled people being sponsored by British employers in sectors such as IT and science also increased.

But experts dashed hopes among Conservative MPs that the sharp fall in net migration would put the party on course to achieve its 2010 election pledge to reduce the figure to less than 100,000 by 2015.

Sarah Mulley, associate director at Institute for Public Policy Research think-tank, said the Government’s progress towards its goal was being driven by falling numbers of international students and warned this will have only a short-term effect.