The RSPCA wants an EU ban on battery hen cages, due to come into force in 2012, to be extended to all hen cages, including the new higher welfare "colony enriched" cages which have been produced to come into line with the legislation.

However, poultry farmers say that if the RSPCA's campaign is successful it will drive poultry farmers out of business and only serve to increase egg imports from countries which do not have the same high welfare standards as the UK.

Robert Newbery, the chief poultry adviser on the National Farmers' Union, said: "The RSPCA is being short-sighted and irresponsible in calling for enriched colony systems to be banned at a time when our members are doing their level best to respond to consumer demands, which means supplying eggs to all ends of the market.

"The egg industry has to reflect diverging consumer needs for higher welfare eggs, but also for affordability. Sales in free range and conventional indoor eggs are both growing respectively, reflecting that some consumers wish to buy higher welfare while other consumers, who have to watch the pennies especially in this current financial climate, opt for affordability.

"Banning the new enriched colony system, which at £15 to £25 per bird and which our members are making considerable investments in, would only serve to export our egg industry to outside the EU or UK, where welfare standards may be well behind our own. With food security an issue, we need to do all we can to safeguard UK supply not force production abroad."

Yorkshire poultry farmers were similarly dismayed at the RSPCA campaign.

Peter Kershaw who farms from near Huddersfield, said that getting hold of the colony systems was hard enough as they are difficult to come by. "If the ban on all cages happens then where are the birds and the eggs going to come from? If this happens there will be a large shortage of eggs in this country and it could put people out of business. There is no new money in the industry to go into it.

"The conventional cages will have to go by 2012 even when there is a lot of life left in them. They ought to just let them fizzle out and the new ones can be brought in when they are finished with."

Nick Fletcher, who farms from Dalton near Thirsk, said: "Anyone who thinks this is a good idea must have a lot more money than the rest of the country. The cost of producing free range eggs is a lot higher and the price of a new cage system is also high."

Alice Clark, a senior RSPCA farm animal scientist, said: "Enriched battery cages are little better than the notorious conventional battery cages. Little will change from the hens' point of view.

"So we are calling on the government to ban all cages and are urging consumers not to buy eggs produced from them, especially as eggs are widely available from higher welfare barn and free-range systems."