About 200 pig farmers gathered outside Downing Street earlier to protest against falling pork profits.
The farmers were joined in their protest by Winnie the pig
Farmers' leaders say the industry is in "meltdown", and some warn that so many farmers are quitting that there may be a pork shortage by the end of the year.
Feed prices have doubled over the past year and farmers say they are losing more than £20 on every pig raised.
Also at the the protest was Winnie, a nine-year-old pig who has attended previous farmers' protests.
A petition calling for support for pig farmers was presented to Downing Street prior to a demonstration at Westminster.
As well as the feed price problems, British farmers also abide by stricter welfare regulations than those in other EU countries, making their pigs more expensive to rear.
And industry experts say that although supermarkets have recently raised their prices significantly, only a fraction of that is finding its way back to the pig farmers.
The increase in animal feed is a result of rocketing grain prices on world markets.
David Feakes, of the Norfolk Pig Discussion Group, also said the price of pork had fallen in real terms.
British Pig Executive chairman Stewart Houston said many farmers would lose their livelihoods without an increase in the price of pork.
"We have reached crisis point. Without an increase, farmers stand to lose approximately £200 million in the next year, and many face the prospect of going out of business.
"Then consumers will lose the choice to buy higher-welfare Quality Standard Mark pork, bacon and ham.
"Two-thirds of all imported produce would be illegal to produce in the UK as it doesn't meet our higher welfare standards."
A cross party Early Day Motion tabled by British pig industry supporter Richard Bacon MP - Tory MP for South Norfolk - will also call for the government's support for British pig farming.
Richard Longthorp, a pig farmer from Howden in Yorkshire, said: "We don't want any special treatment. All we are asking for is a fairer share.
"Feed represents around 50% of our costs and this has gone up massively. Prices are going up but we're not getting a share of it.
"If things don't change we'll see a lot of farmers going out of business."
Reg Joseph, who has spent his life in the industry, said he had come to Downing Street from Lincolnshire and others were arriving from Scotland.
He told the BBC: "We want better labelling at the supermarket level, and for the end user, which is the housewife, to be told the truth."