The number of foreigners given UK passports shot up by more than half last year, new figures reveal.
A total of 203,865 people were granted British citizenship in 2009 - an increase of 58% on 2008.
Tens of thousands more immigrants were also given the right to settle in the UK - the total was up 30% to more than 190,000.
Of those, grants of settlement linked to jobs rose from 37,000 in 2007 to more than 60,000 in 2008 and 81,000 last year - despite the recession.
Quarterly immigration figures, published by the Office for National Statistics, also showed a 30% increase in student visa numbers last year compared to 2008.
In the final three months of 2009, 61,715 student visas were issued - an astonishing rise of 92% on the same period in 2008.
The figures prompted questions over the effectiveness of the new points-based system for student visas.
They also revealed a shift in arrivals from Eastern European countries. The number of Poles registering to work fell by a quarter at the end of last year, but arrivals from Latvia and Lithuania more than doubled.
Critics said the rises showed immigration was "running out of control" and questioned whether so many work visas should have been issued during the recession.
But ministers pointed to falls in asylum applications, which hit their lowest level since the early 1990s.