It cannot have escaped your attention – assuming you pass through the portals of your local supermarket now and then – that there is a lot of cheap cheese about this summer. And at remarkably low prices.

Nearly every retailer has been offering huge discounts, half-price deals and other sweeteners to shift the stuff. But what has been going on at the retail end is having disastrous consequence back on the farm.

The British market is being flooded with cheap imports from New Zealand and Ireland. Irish imports increased by 25 per cent in the first five months of the year while New Zealand's almost doubled.

No matter that, for the most part, the quality of what they send us compares very unfavourably with what we produce here.

And that quantity arriving here is leading to British processors cutting their prices in order to compete and retain crucial market share. But this is reaching ludicrous proportions.

Most mass market cheese is already comparatively cheap. But halve the price, as a lot of stores have been doing, and you are putting the price clock back by perhaps eight or nine years.

Meanwhile the returns to farmers are being ruthlessly forced down, with Milk Link's cut of a halfpenny a litre merely symptomatic of the fact that – with no national co-op to wield muscle on their behalf – farmers are still at the total mercy of the market.

Now you may well accuse me – and indeed dairy farmers – of crying wolf. But let the figures speak for themselves.

We have been losing roughly five per cent of our dairy farmers every year as producers have found themselves unable to make a living from the meagre figures on the milk cheques.

In historical terms milk production is at its lowest ever point and, as Stephen Wyrill from the Tenant Farmers' Association points out, it's difficult to reconcile that situation with the need to assure this country's long-term food security.

There appear to be some strange games of brinkmanship going on here – though it's hardly a game for the farmer who has to throw in the udder wipe after years of battling against ever-mounting obstacles. And if you thought things couldn't get any worse and will soon pick up then I have to tell you that you are being ridiculously optimistic. For hovering over the farming sector is a new cloud – one containing the costs of complying with the nitrate vulnerable zones legislation.

This is intended to protect water courses from even the most minute degree of contamination from agricultural run-off. In vain farmers have contested them. In vain they have challenged the lack of scientific evidence suggesting the existence of any public health problems. In vain have they argued that a few years ago it wouldn't even have been possible to measure the tolerance threshold that has been set. The regulations are being enforced – at an average cost to the farmer of £50,000 – which, for a tenant farmer, is the kind of cash that makes a difference between staying in business and getting out.

Of course it's not all good news on the retail front, where milk (as opposed to cheese) prices have been slowly edging up. In the last year they have increased by an average of five pence per litre. Bottled milk is still cheaper than bottled water but a calculation will show that when the retail price increases and the producer prize decreases are taken together the retailers have been able to clean an extra 10p a litre on milk sales.

And that, according to some pretty reliable calculations, means that the supermarkets are now trousering an extra annual margin equivalent to £150,000 for every dairy farmer in the country.

So when the cheese, and the cream and the yoghurt and the milk start to run short on the shelves and consumers start to wonder what's gone wrong, there's the answer ready and waiting for them.