Britain should set an example to the world by reversing its steeply-rising population growth and allowing no more people into the country than leave

Jonathon Porritt, chairman of the Sustainable Development Commission, said it was entirely possible to be "very progressive" on immigration while still having a policy of "zero net immigration" and no further population growth. Porritt told an audience at the Cheltenham Science Festival, he would like to see Britain's population on a declining trend, instead of increasing to 65 million in ten years and to 70 million by 2031. Porritt, who is a patron of the charity, the Optimum Population Trust, warned that globally spending on family planning was "massively" lower than the £8 billion spent on HIV/AIDS. Yet it should be around £12.5 billion to £15 billion if the world was to avoid a population of more than 9 billion or more by 2050. Porritt warned that in sub-Saharan Africa and the Middle East, population trends were increasing "disastrously" because of low spending on family planning. In Kenya and Ethiopia, spending on family planning was now running at 2% of spending on HIV/AIDS. As a result the population of Kenya, which had been thought to be around 40 million by the mid-century was now expected to be 80 million. "We are guaranteeing an unstoppable flow of problems like HIV and AIDS into the future," he said.