The formal oath – or affirmation of allegiance to the Queen – became a legal requirement for anybody applying for UK citizenship in 2004.

Last year, Northamptonshire County Council recorded a five per cent increase in the number attending British citizenship ceremonies from 875 in 2006 to 920.Only Leicester held more in the East Midlands, with 1,580 becoming British citizens in 2007.

Pam Allen, superintendent registrar, who conducts the ceremonies for Northampton in the Guildhall and County Hall, said: "The general response from people who take them is wonderful. We didn't think we would have to put on as many as we have.

"It's very important that we wave the flag a bit and be seen to be patriotic. People actually are proud to be British so the increase is about more commitment and it's really rather nice."

Since the ceremonies began, county registrars have completed almost 4,000 events and almost all of the 16 people in Northamptonshire waiting to become full British citizens will attend a ceremony this week, with many due to take place at County Hall in Northampton today.

Brian Binley, Conservative MP for Northampton South, said: "It simply confirms that Northamptonshire is a magnet for immigrants and I suppose that is a compliment, but it is causing major problems. We have to take every opportunity to make sure that people are not here illegally and I would also like an English test in there as well."

The county conducted the 15th highest number of ceremonies of any authority in the UK outside Greater London.

Sally Keeble, Labour MP for Northampton North, said: "If people are making a commitment to the UK then that's obviously preferable to having people who are completely transient.

"I've always thought that people often come to work in Northamptonshire and stay because it's a good place to live."

A spokesperson from Northamptonshire County Council said: "It's a chance to encourage people who have settled in the UK to play a full part in their community and to know that they are welcome."