Local authorities like Birmingham which have diverse populations bear the financial brunt of dealing with immigration and equality, Trevor Phillips said in his speech yesterday.

Speaking in Birmingham at a seminar on equality and local government, the chair of the Equality and Human Rights Commission said the pressure on local authorities to pay for services to cope with increasing numbers of migrants was causing services to "creak" because of insufficient funding.

And he warned that this could result in inequality, fragmentation and segregation. Alan Rudge, the Birmingham City Council cabinet member for equalities and human resources, chaired the meeting at the Centre for the Deaf on Ladywood Road.

He said Birmingham was the most diverse city in the country, and as such was particularly badly affected by the shortfall in government immigration estimates, and hence funding.

Coun Rudge said many aspects of the council budget, including housing, care, education and transport were under pressure because the Government had underestimated the amount needed by the immigrant community. He also supported Mr Phillips's campaign to expose the myths behind immigration, such as stories of asylum seekers being given council houses in favour of deserving British people.

Mr Phillips said he had never seen any of these allegations backed up with evidence, and said he believed many public misconceptions about immigration were driven by "careless media and racist political parties".

He announced plans to work with Coun Rudge and the LGA to look into these "myths" and see if there was any truth to them before the European elections next year, to stop lies being exploited by right-wing political parties.

"We need this debate to be based on not what someone heard at the pub, but on facts," he said. He said the Equality and Human Rights Commission and the LGA would be holding a joint inquiry into the way housing is allocated. Mr Phillips said: "One area where this idea of unfairness is most frequently alleged is in housing allocation.

"Specifically that white families are cheated out of their right to social housing by newly arrived migrants." The debate, he added, needed to be informed by "robust evidence".

Outlining his views on immigration policies, Mr Phillips voiced his support for Tory leader David Cameron's views about population increase and proposals to manage immigration. Mr Phillips said population growth had to be managed decades ahead, and was surprised to hear such a "socialist" level of planning from a Conservative leader.

He praised Mr Cameron's awareness of the issues involved and said he was pleased to see the issue of immigration being deracialised.

But he warned that outright immigration caps would be inflexible, and unsuitable to deal with the problems immigration poses.

Mr Phillips said Mr Cameron wanted to drain the issue of immigration of racial "toxicity" but warned that electoral campaigning would be the true test of party leaders. "The test of their commitment isn't really what they say, but what their troops do next year."

A spokesman for the Department for Communities and Local Government said: "Trevor Phillips says in his speech that he has never seen 'any reliable evidence' to back up claims that councils are unfairly allocating housing. While local government has always maintained they have operated allocations fairly, we agree it is important to deal with perception, and welcome work that helps promote a more informed and measured debate."