On 1 January 2012 it will be illegal for farmers across Europe to keep hens in conventional barren battery cages. Farmers in the UK are believed to be prepared for the new law but elsewhere in Europe a large number of producers are not ready - meaning an estimated 84 millions hens* will still be kept in cruel cramped cages below even minimum welfare requirements.

A YouGov survey about hen welfare has revealed that 78 per cent of people in England and Wales would support a trade ban on illegal eggs.

With just a month to go until the barren battery cage ban the RSPCA is calling for the dithering European Commission to take action.

David Bowles, director of communications at the RSPCA, said: "We want quick, decisive action to stop the trade in these illegal eggs as well as rigorous enforcement of the new legislation and tough penalties for those farmers flouting it.

"Shoppers are increasingly buying higher welfare eggs in the supermarket – allowing illegal eggs into the UK would be a slap in the face for the public and a backward step for millions of hens. The RSPCA wants to see action now – before it’s too late."

The Welfare of Laying Hens Directive outlaws the use of conventional barren battery cages in favour of other systems - barn, free-range, organic or so-called ‘enriched’ cages.

‘Enriched’ cages give hens a nesting, scratching and perching area and a little bit more usable space, but still amounting to less than an A4 sheet of paper per bird. The RSPCA believes no hen should be kept in a cage but the new legislation is a step in the right direction.

Most whole eggs on sale in the UK are laid by British hens so are expected to be perfectly legal however it may be more difficult to trace the origin of any imported liquid egg used as ingredients in products, particularly because some European producers may have a mix of some legal and illegal cages at the same farm.

The RSPCA want the new battery cage legislation to be strictly enforced by European Union member states, however it can take more than a year to bring a case to the European Court of Justice and in the meantime millions of illegal eggs laid by hens kept in illegal conditions could be used as ingredients in products which find their ways on to the shelves in the UK.

To stop this happening the RSPCA wants to see a trade ban imposed to stop illegal eggs being sold outside the country where they were produced.

Alice Clark, senior scientific officer at the RSPCA, said: "Farmers have had 13 years to get rid of their cruel barren battery cages, there really is no excuse for any producer to still be using them after the deadline.

"This historic piece of legislation is meant to improve the lives of millions of hens, it’s outrageous that next year almost a quarter of all egg production in Europe* is expected to come from illegal barren battery cages.

"It adds insult to injury that with just a month to go there is no measure in place at a European or member state level to stop these illegal eggs, coming into the UK whole or as ingredients in food such quiches, ready-meals and cakes."

To find out more about RSPCA's campaign against cages, or how to contact politicians to call for a trade ban, please click here.