Applications for British citizenship from foreign nationals have fallen since English language testing was brought in, the Home Office has said.
New British citizens are required to pledge allegiance to the Queen
The number of people asking for citizenship dropped 8% to 135,085 last year when the department's so-called "Britishness test" was introduced.
This followed a 28% increase in 2003, the Home Office said.
But the number of those granted citizenship grew by 12% on 2003 to 140,795, figures show.
The higher number was partly due to a backlog in applications from 2003.
Figures also revealed a 35% increase in numbers of applications refused, which stood at 12,050 last year.
Since July last year, all would-be British citizens have had to meet an international standard of competence in English.
The Home Office figures showed that nearly six out of 10 of those who were born overseas, but have lived in the UK for six years or more, are now British citizens.
Immigration Minister Tony McNulty said the figures showed that many settlers in Britain wanted to make a commitment to the country.
"It is a commitment that is now recognised and celebrated through our new citizenship ceremonies and the requirement to have basic knowledge of English will help new citizens participate and contribute more fully to British life."
The citizenship tests were introduced by David Blunkett
According to the Home Office, 63,366 people granted nationality have taken part in the citizenship ceremonies which began in February last year.
They require people to pledge allegiance to the Queen and to vow to uphold British democracy.
An analysis of the breakdown of those who made bids for citizenship found few applications from nationals of other developed countries, such as Australia, New Zealand, the US, Canada or other EU states.
Of all those granted a British passport last year, a third were from African countries, a quarter from the Indian sub-continent and 11% from European countries outside the EU.
One in 10 successful applicants were from Pakistan, another 10% from India and a further 8% from Somalia.