Ministers have announced plans to ensure that new British citizens have a working knowledge of English.

Home secretary David Blunkett welcomed proposals to set a "citizenship test" for those seeking a British passport.

The move forms part of a controversial drive to ensure that immigrants who choose to remain in the UK fully understand what it means to be British.

The announcement follows a study commissioned by the home secretary.

Headed by Sir Bernard Crick, the "life in the United Kingdom" advisory group makes recommendations on how to ensure new British citizens possess sufficient knowledge of English, Welsh or Scottish Gaelic.

It says that new citizens must develop "an understanding of the basic history of the United Kingdom can strengthen commitment to common values".

Blunkett insisted that diversity is not incompatible with the plans.

"We're trying to ensure that people are capable of integrating in society, getting further education, obtaining a job, above all being able to communicate with the world around them, which is not only crucial for them but it's absolutely vital if we're going to have social cohesion and a welcome for those from across the world," he told the BBC's Today programme.

"I believe we can have integration with diversity. We don't expect that somehow all the colour literally will go out of Britain in terms of the multifarious and very different religions, cultures, backgrounds, nationalities, that have made up this island.

"But we want people who can actually be part of the world we live in - this is about identity and a sense of belonging."

Blunkett joined Sir Bernard at an English class in north west London where the committee's final report was unveiled.

Sir Bernard said citizenship is something which should be earned.

"Residents who meet the requirements for naturalisation should be encouraged to apply for citizenship and to take on the responsibilities as well as the privileges," he said.

"Use of the English language itself is possibly the most important means by which diverse communities participate in a common culture - that is why it is so important that new citizens should have a sufficient knowledge of English, Welsh or Scottish Gaelic.

"We do not want the burden to be onerous but plainly citizenship is more esteemed and valued when it is earned and not given."

The government wants new citizens to view their status as a life-changing event.

It also believes they should have a knowledge of their rights and duties as a British citizen.

Sir Bernard added that his report was not an attempt to "define Britishness".

"We're not trying to define Britishness, we're trying to define what people need to settle in effectively," he told the BBC.

"Some will pick it up anyway, some will be so helped by their own communities in this country that they will have very little contact outside their community.

"We are very carefully saying that one of the big objects of this report...is integration in the sense of people feeling secure in their own identities, but also sharing a wider identity of the civic institutions and the tolerant habits and the whole of political life that we have in this country.

"We are not in favour of multiculturalism as anything like separate but equal, but equally we are not assimilationist."

Liberal Democrats gave the announcement a cautious welcome.

"Preparing new arrivals for being British is very important and should be taken seriously. As such, these suggestions deserve a warm welcome," said home affairs spokesman Simon Hughes.

"Everybody will benefit from greater proficiency in English, and a better understanding of what makes the UK tick.

"The courses and tests must be flexible so that they do not discriminate against people such as grandparents from another country who come to the UK with little previous formal education.

"If we are going to have citizenship ceremonies to welcome new arrivals once they have been in the UK for 5 years, then why not have citizenship ceremonies to welcome new adults as they leave school and become able to fully participate in the country they were born in?"

The new approach mirrors similar schemes already in operation in countries such as Australia, Canada and the United States.

But it is opposed by human rights and groups representing minority groups who claim it will undermine cultural diversity.