David Coleman is keen not to be dismissed as a right-winger. The reader in demography at the University of Oxford expressed concern this week about the rate of immigration into the UK.
Dr Coleman, a consultant to MigrationWatch, warned that the current rate of immigration was equivalent to creating a city the size of Cambridge every six months. He has called for "an open and frank debate, based on the facts" about immigration.
Dr Coleman's work examines the potential of immigration for solving problems of population ageing, providing essential labour and, provocatively, inviting "unwanted foreigners".
He doubts that immigration can fix the first problem because immigrants age too. He said: "Immigration as a solution to a generally ageing population can be rejected on demographic grounds. If you wanted to preserve the ratio of people of working age to those they support, you can do it - but only at the level of 1.2 million new immigrants every year up to 2050, which would double the population to 120 million."
Instead, society should change to reverse the decline in the birth rate and stabilise the population. He said: "Where families are supported, where women can combine work and children, where men, sometimes, wear the aprons, birth rates are higher, most women work and many births are outside marriage. Confining women to home, and births to marriage, keeps cradles empty."
Dr Coleman, who was born in London in 1945, studied zoology at the Oxford University, before spending a year on Voluntary Service Overseas in Nigeria. He did a PhD at the London School of Economics, became a physical anthropology lecturer at University College London, then returned to Oxford in 1980.
Dr Coleman is a former adviser to the Conservative government. He has also worked as a consultant for the United Nations and private business.