Indian and Pakistani migrants accounted for nearly a quarter of all new recipients of British passports, the latest figures have revealed.
More than 28,000 Indians and just over 18,000 Pakistanis were granted UK citizenship out of a total of 193,000 in 2012, according to the figures by Eurostat, the European Union's official statistics office.
Indian and Pakistani nations were followed by immigrants from Nigeria and the Philippines, who accounted for 4.6% and 4.2% respectively of all British citizenships.
The number of British citizenships granted to migrants was the highest of any nation within the European bloc of nations which granted a total of 818,000 citizenships.
Carlos Vargas-Silva, deputy director of the Migration Observatory at Oxford University said: "The UK is the leader in terms of people acquiring citizenship in the EU and one of the reasons this is happening is because of migration from the Commonwealth.
"They come to join established networks and families so they want to acquire citizenship."
Germany granted the second highest number of new citizenships with 114,000, followed by France on 96,000.