In the remoter areas, such as the uplands of the West Country, Wales and the North, the crisis in farm incomes could lead to so many farmers leaving the land that the economic, social and environmental foundations of rural life would vanish with them, Mr Gill said.
Parts of France, particularly regions such as the Massif Central, have suffered so severely in recent years from the numbers of farmers abandoning agriculture that hundreds of French villages are now moribund, many with only a handful of inhabitants.
"With the pressure on incomes at the moment, it is a real possibility that this will happen here," Mr Gill said. He was speaking at the launch of an emergency audit of the NFU's 83,000 members in England and Wales to quantify properly the effects on them of British farming's acute economic problems. A survey by The Independent last Saturday indicated that farmers were now losing money on every commodity they produce apart from wheat, and the Environment minister Michael Meacher said farming was probably going through its worst period since the thirties.
The results of the audit will be used by the NFU to press its case with the Government for relief measures, particularly in the livestock sector, which is the hardest hit. Farmers will be staging a massive demonstration at the Labour Party conference in Bournemouth at the end of this month.
"The French found out that if they did not recognise the needs of their rural areas, they got what in the end they termed `desertification'," Mr Gill said. "That is not something I want to see in parts of Britain and I don't believe the British public want to see it either, but the ultimate end of the farm crisis is depopulation of the more remote areas of the countryside."
Although he refused to say exactly how many farmers are going bankrupt or face that risk until the results of the audit are in, Mr Gill said many farmers had gone under this year and many others were clinging on by their fingertips.
If the process continued, he said, agriculture would disappear as the focus of the rural economy. That would affect all the industries that depended on it, and then "the people who support local businesses, the village shop, the village garage, the village pub, the people who go to the local church, who partake in the village hall, who help raise money for all those aspects and indeed, who provide children for the village school".
He added: "Time and time again, when we've seen the more remote village primary schools close in particular, that is the death knell for those rural communities, because it is harder and harder for someone to come in when they may have to transport their primary school children considerable distances and are not prepared to do that. So you begin to spiral down."
The environmental damage would be similarly great. Maintenance for stone walls, hedges and traditional farm buildings, which many people feel ought to be preserved, would end. And the environmental benefits of having livestock graze the uplands would be lost.
When the French tried to entice families back to abandoned areas, they found it cost more than maintaining the original communities would have done because the infrastructure had gone, he said. "For that to happen here would be a disaster for the countryside, for the taxpayer, for the people on the farms and for those rural communities."
Tomorrow night Mr Gill will be having talks about the current crisis with Nick Brown, the Minister of Agriculture.Reuse content