I spent most of my childhood on that farm, basically mucking around in barns and generally getting the feel of living in and on a farm.

I suspect that back then, in the 1980s, things weren’t quite so bad for the industry, but it still gave me a strong sense of the hours a farmer must work. The amount of work is just absolutely phenomenal and I got a sense of the level of effort and commitment involved 365 days a year.  But I also saw what a rewarding lifestyle it can be if things are managed properly, so I got a real affection for farming and life in the countryside.

I also developed a sense of indignation at the way farmers are treated. That treatment does have an impact on other issues like where we get our food. I’m very committed to the idea of fair trade internationally, but we need to think a little bit more in terms of fair trade within the UK as well. If you look at the price obtained for produce at the ‘farm gate’ and at the auction market, and then see what goods are sold for on supermarket shelves, there is something very wrong there. This differential could have a damaging effect on an industry that is important economically, socially and culturally.

Part of the problem is that we don’t have any balance in the market. To say we have a free market is not true; it’s a very imbalanced market. It was well known that four or five huge supermarkets dominate the retail sector. But there are other near-monopolies, too. I think two companies own 80 per cent of Britain’s abattoirs, for instance, but they don’t get much in the way of headline attention. On the other side of the equation are thousands and thousands of small producers who are easily picked off by the giant companies they deal with.

One example of how this works out was when we had foot-and-mouth two years ago. The disease was restricted to Surrey, but because of the situation where farmers couldn’t use their livestock very easily because of movement restrictions, they could often only sell to one buyer. Those incredibly powerful buyers took advantage and prices dropped by anything up to 80 per cent.

In the end, it’s all about the fairness in the marketplace and what you do about that. I think the most powerful thing we can do about it is to bring in a food market regulator to ensure that people pay fair prices. Some other European countries have similar mechanisms that basically ensure that producers are not exploited and that they can get paid at least cost price for their produce. That also means, for example, keeping a check on how farm-gate prices and supermarket prices compare.

Such a regulator would need to have the power to really do something about it were problems to arise, in the way that Ofcom has the power to regulate broadcasters. The mechanisms at present are pretty toothless mostly and we need more than that, we need something that will be able to be quite muscular and who’ll be good, something that would be big enough to protect the farming industry.

The point is to try to equalise power within the food market from the consumer to the producer and all points in between. That means looking hard at what’s a fair price. If the shelf price for a litre of milk were only 30 pence, then paying farmers only 17-18 pence would be difficult, but it would be tolerable because that would reflect the consumer price. But farm-gate prices don’t really reflect consumer prices right now.

A radical break up of supermarkets is unlikely and that wouldn’t be the right thing, either. In many ways the supermarkets do good work, but they clearly abuse their power. The result is that we’re losing vast numbers of farmers. For example, we’ve lost about a billion litres of milk production in the past four years. That’s not because people are drinking less milk, they’re actually drinking more, it just means they’re consuming more from imports. This applies to a lot of aspects of agriculture, particularly livestock farming, where we’re losing capacity but we’re not reducing consumption. The only answer to this is to import - which is very bad for the environment and very bad for our farming economy.

A regulator wouldn’t solve all our problems and we don’t want to create a new era of expensive food when consumers are already hard pressed. But if we are to achieve a real free market then that means you have to have someone to be a referee.

It is ludicrous to think that we’re losing farming capacity in this country when we face the prospect that world population will go up by 50 per cent in the next 40 years and demand for food will double by 2050. As it happens, a rising population ought to be good news for a farmer anywhere. We can also see an enormous amount of innovation in farming, not just in terms of diversification. For example, we’re developing a whole culture of farmers’ markets and buying direct from the producer. We can ensure quality of produce and fairness within the market if we buy direct from the producer.

I think innovation in farming is definitely rocketing up and I think within farmers’ clubs in the country there’s a real sense that the next generation is going to be made up of really good business people. They are innovative and creative, but also prepared to look after the countryside and take pride in what they’re selling.

We need to enable people to be in the countryside by allowing people to make a living out of producing food. If we allow our capacity to produce food to continue to decline we’re going to be in a situation where we find ourselves spending far more money internally buying far more food or import from countries where standards aren’t as high as in the UK. The starting point for that is fair trade at home.

This article is based on an interview by Rob Lyons.

Tim Farron is Liberal Democrat spokesman on environment, food and rural affairs.