The Women's Institute wants a fairer deal for dairy farmers

Isla Arendell, 39, a member of the Women's Institute from Tutshill, Gloucestershire, said her demonstration showed milk is now as cheap as water.

"British dairy farmers are paid 18p per litre, whereas 10 years ago they were paid 24.5p per litre," she said.

The Department for Environment, Food and Rural Affairs (Defra) said markets determine prices, not government.

More than 72,000 people have signed a National Federation of Women's Institutes (NFWI) petition, calling on the government to ensure a fairer deal for dairy farmers.

The NFWI is urging action to ensure a sustainable dairy industry where farmers receive a fair price for their milk.

"We are concerned that in a few years' time there will be no more milk production in Britain," said Ms Arendell.

Dairy farmer Colin Salmon, 49, from Glastonbury, Somerset, who attended the petition launch, said: "I have been a dairy farmer all my life and it's getting too much, what with all the regulations and lower prices for the milk.

DAIRY FARMING In 1985 there were 28,000 dairy farms in England and Wales By the end of 2006 there were 13,000 Nearly a third of dairy farmers plan to leave within the next two years

"If the price of milk goes down any more, we shall be getting out because we can't afford to stay in business, he added.

"If it drops again, I'll probably call time on it."

Mary Rosevear, of the Small Farms Association, said: "About 25% of our members every year are going out of dairy. It's just not economical."

Caroline Spelman, Shadow Secretary of State for the Department for Communities and Local Government, received the petition.

"What other product do you know that has gone down [so much] in price?," she said.

"A third of farmers leaving the trade tells its own story."

Price negotiations

A spokesman for Defra said: "Price negotiations between producers and processors are a private commercial matter in which government cannot get involved, as long as the competition rules are respected.

"We therefore will not be appointing a regulator for the milk market.

"We recognise that the next few years will be challenging for the sector and that pressure on farmgate prices will remain.

"Defra is aware of the cumulative burdens facing the industry and will continue to work with the industry to try to minimise the impact but some restructuring of the industry is inevitable."