The advertisement is in the form of an open letter to consumers.

It says:

'British consumers are more concerned than ever before about where their food comes from. When it comes to pork, bacon, sausages and ham, the Pigmeat Quality Standard Mark delivers excellent standards of welfare. That means the pigs are well treated and provided with high quality feed.

In fact, feed – mostly wheat – is about half the cost of rearing a pig. But wheat prices have rocketed worldwide: as a result, pig farmers’ businesses – which get no subsidies – are under serious threat.

Due to price pressure from supermarkets, farmers are now being paid around £1.10 per kg for a pig that now costs them £1.44 per kg to produce.

For every pig a farmer rears and sells, he is likely to lose over £20.

This can't go on. Today, we're launching our campaign to press the supermarkets to ensure that pig farmers are paid a fair and sustainable price. Continual pressure on the price of pork, bacon and ham will squeeze the life out of pig farming.

We need the supermarkets to pay an extra 34p per kg to help preserve British pig farming. If this price rise were passed on to shoppers, it would only mean between 7p and 17p on the pack price of typical pork products.

We think it is a small price worth paying and we’re asking British consumers to back us.'