The figures are a fresh illustration of how difficult it will be for David Cameron to cut net immigration to under 100,000 a year.
The European Union’s Eurostat data agency revealed that a total of 985,000 foreigners were granted citizenship in Europe in 2013.
Some 207,500 of them had successfully applied for UK passports – the most since records began in 1962.
Eight per cent were nationals of other EU states, mostly eastern Europeans.
Only three per cent of UK citizenship applications were refused in 2013, reigniting criticism that British conditions are too soft.