Head of the NAO Amyas Morse - who last year declined to sign off HMRC's accounts because of tax credit fraud and error - said HMRC faced "significant" challenges.

BBC: Margaret Hodge tells HMRC to 'get a grip' on tax credit fraud

He believes that black Americans made a great historical error in the 1960s when they relaxed their campaign for civil rights and integration at the first sign of progress, turning their back in many cases on the "blacks only" hotels and restaurants which had sustained them during segregation in favour of the businesses which were newly opening to them.

BBC: Black Washington looks to Obama