According to the Higher Education Statistics Agency, there were 39, 090 Indian students on UK courses in 2010-11, 13% of the total non-EU student population and second only to China.

BBC: Mr Johnson with schoolchildren at Amity University

Mrs May expects her new measures to cut non-EU student numbers by at least 70, 000-80, 000 a year, or more than a quarter of the non-EU total (EU citizens don't need visas to study in Britain), though both numbers and policy details remain a work in progress.

ECONOMIST: Student visas

But by far the biggest route for non-EU entrants into this country has been the student visa route.

BBC: In full: David Cameron immigration speech

For example, the student visa system, which admits half a million non-EU students a year, needs a much more effective means of testing whether the applicants are genuine and intend to return home.

BBC: Migrations figures remain steady