 He was elected Member of Parliament for Kensington North in 1970, then for Mitcham and Morden in February 1974.Douglas-Mann spoke out on the plight of refugees.In 1971, in the East Bengal (now Bangladesh) refugee crisis (during the Bangladesh Liberation War) he said it was "the worst tragedy the world had known" and the following year, when Idi Amin ordered the expulsion of Asians from Uganda he said that returning them would be "like sending Jews back to Hitler in the 1930s" Having been involved in housing case work as a solicitor, following Norman St John-Stevas introduction of the parliamentary select committees in 1979, he served on the PSC concerning the environment because housing was part of its remit.