Speaking at the British Science Festival on Friday, 8 September, in the event Is Brexit an opportunity for sustainable food production in the UK?, organised by the Sussex Sustainability Research Programme, Professor Goulson is expected to say a version of the Common Agricultural Policy could continue after the UK leaves the EU but only if it supports smaller and more sustainable farming rather than giving the bulk of subsidies to large multi-national companies and rich landowners.

Professor Goulson said: "Industrial farming is wiping out wildlife, damaging soils, and contributing hugely to climate change, and I don’t understand why we should continue to subsidise that system with taxpayers' money. There is no other industry like it. We decided a long time ago that the car industry and the coal industry could no longer be subsidised. All other industry subsidies have gone except for agriculture. If we are to continue with CAP after Brexit, it needs to be entirely reformed.

"There is exciting potential to rejuvenate farming in Britain without the need to seek agreement from 27 other member states, there is the opportunity to do something really radical and move away from industrial farming, revive rural communities and get many more people back into growing local, healthy food."

He added: "The current industrial farming is highly inefficient at feeding people, producing food that has been drenched in repeated applications of pesticides. Much of the harvest is fed to livestock, while about one third of the food grown is simply thrown away. Smaller-scale, labour intensive farming systems such as permaculture in which multiple crops are grown together are both more productive and far more sustainable, maintaining healthy soils, having far fewer pest problems and supporting wildlife. Small farms in the developing world already account for a large majority of the world’s food. During the Second World War, gardeners and allotment holders in the UK produced 10 per cent of the food we ate from just 1 per cent of the land."

Professor Goulson said the current system was too reliant on the agrochemical industry as the only source of information for farmers on how to increase yield – four in five agronomists, the people on whom farmers rely for their advice, currently work for chemical companies. The Professor of Biology called for a return of Government-run experimental farms and funding for a new advisory body to offer impartial advice to farmers on how to farm productively and sustainably after Brexit.

He said: "The failure to move to a more sustainable system now could have drastic consequences within 50 years. Farmland bird populations have fallen by 58 per cent since 1970, butterflies are now scarce and some bees have gone extinct. Realistic projections suggest more than half of life on Earth will be extinct by the end of the century. Without pollinators, future farmers will be severely limited as to what they can grow. If soils continue to degrade, they will be able to grow little or nothing. Our grandchildren will not think kindly of us if we leave them an impoverished planet."