Indians were the single largest group to get British citizenship in 2006, latest official figures indicated.
While 15,125 from India were given British citizenship, Pakistan came second with 9,050 of their nationals changing their citizenship.
Other major groups were from the Philippines (8,840), South Africa (7,670), Nigeria (5.870) and Sri Lanka (5,720).
In the last one decade of Labour rule, one million foreign nationals have been given British citizenship.
In 2006, more than 150,000 people obtained a passport which took the total of foreign nationals given British citizenship to 1,020,000 since Tony Blair assumed the rein.
Andrew Green, chairman of Migrationwatch UK said passing one million new citizens since 1997 was a watershed for government policy.
"It is hard to know whether this increase is incompetence or deliberate deceit. Either way we will pay a high price in terms of social harmony," he said.
Immigration Minister Liam Byrne said, "British citizenship is a privilege and it is right that it should be recognised and celebrated as a crucial stage in a person's integration into British life.
"It's also essential that migrants wishing to live in the UK permanently recognise the responsibilities that go hand in hand. Requiring a good grasp of English ensures that they are able to play a full role in society and properly integrate into our communities," he added.