Dear Sir,

Your article "There are 95% fewer illegal student migrants than Britain thought" confuses the number of students who overstayed their student visas with net migration.

The Office for National Statistics does not produce estimates of student over-stayers. The ONS estimate referred to in the article of "more than 90,000 over-stayers per year" was not a measure of students breaching visa conditions. It is the difference between the estimate for Long-Term International Immigration for Study and long-term emigration of those who originally came to study.

ONS has long acknowledged that the current demands of migration statistics are pushing the International Passenger Survey beyond what it was designed for. There is clearly a need for more timely data and while the IPS will remain a valuable leading indicator of international migration I will be setting out our work plan for migration statistics later this month.

Yours faithfully,

Iain Bell
Deputy National Statistician
Office for National Statistics
Government Buildings
Cardiff Road
Newport NP10 8XG