Seven months after the European Union introduced a partial ban on keeping pregnant sows in stalls, half of European Union countries have still failed to clamp down on pig farms where sows are illegally confined for most of their lives.

The ban outlaws use of sow stalls after the first four weeks of pregnancy, but as with the battery cage ban before it, which was introduced under the Welfare of Laying Hens directive in January 2012, EU authorities have struggled to enforce the new measures. In response to the lack of official action on producers still flouting the ban, the National Pig Association has urged retailers in the UK to ensure all pig meat they sell is traceable and comes from a compliant producer.

New data from the European Commission show only 13 member countries are fully compliant with the pig welfare directive; Austria, Bulgaria, Czech Republic, Estonia, Lithuania, Luxembourg, Latvia, Malta, Romania, Slovakia, Spain, Sweden, and the United Kingdom are all up to speed. Sow stalls have been banned outright in the United Kingdom since 1999.

The Commission started infringement proceedings against nine countries in February — Belgium, Cyprus, Denmark, France, Germany, Greece, Ireland, Poland and Portugal. The Netherlands, Italy, Hungary, Finland, and Slovenia are still being investigated.

Earlier in the year, NPA launched a campaign encouraging retailers and food companies to pledge that they will not import pork from non-compliant pig farms. The association said on Monday it is currently carrying out a number of spot checks, to ensure companies that made the pledge are sticking to their word.