Councils should be given a statutory responsibility to improve community integration, a think-tank said as it published research into the most divided areas in England and Wales.

Policy Exchange said forcing councils to publish regular audits would focus minds on action to ensure a better ethnic mix, for example of pupils in particular schools or staff in public services.

And the Government should compile a comprehensive national analysis of the picture every three to five years, it said as it launched a new Demography, Immigration and Integration Unit.

The unit's head David Goodhart said: "If there's a national consensus that we want to avoid parallel lives, any pressure on them to produce figures and to get councillors thinking about how they can make schools and neighbourhoods more mixed is a help."

Analysis using data from the 2011 consensus - related to 160 places with a population over 20,000 of whom at least 15% were from an ethnic minority - showed there were significant variations in the extent of inclusion, he said.

It also used the findings of previous "index of dissimilarity" work by other researchers.

Boston in Lincolnshire - which has seen an influx of mostly Eastern European workers over recent years - was deemed the least integrated, based on figures including whether individuals held a UK passport, how many households were ethnically mixed and employment statuses.

Others had either seen similar immigration patterns in recent years or had long-established minority communities, mostly of Pakistani origin.

The 10 least-integrated places were identified as Boston, Wisbech, Oldham, Spalding, Bradford, Batley, Halifax, Blackburn, Keighley and Accrington.

The most integrated were mostly prosperous suburbs or small towns around London and Birmingham, with the largest minorities being successful Indians or Europeans.

Top was Amersham, followed by Sutton Coldfield, Loughton, Potters Bar, Letchworth Garden City, Stretford, Bushey, West Bridgford, Rickmansworth and Esher.

Mr Goodhart said: "Ethnic minority integration has shot up the political agenda in recent months and it is useful to know where the biggest challenges and the often quiet success stories actually are.

"As our index shows the integration picture is a mixed one but in some places people, of all backgrounds, fear that society is changing too fast and that too many people are living parallel lives.

"We know that people of similar backgrounds tend to cluster together but we also know that a good society needs a sense of trust and mutual regard that crosses social and ethnic boundaries.

"It is critical that this country retains its traditions of openness and individual rights and some sense of mutual regard between citizens. That is why the government should try to promote mixed communities."

A Department for Communities and Local Government spokesman said: "We are fully committed to doing everything we can to help create an integrated society and the Prime Minister has commissioned Louise Casey to review what more we can do to create less segregated and more cohesive communities in England.

"Since 2011 we have provided over £50 million to support integration projects and the Government recently announced a new £20 million community fund to help teach English to isolated women."