This week, the European Commission wrote a formal notice letter to Belgium, Cyprus, Denmark, France, Germany, Greece, Ireland, Poland and Portugal telling them to take action to ensure the Directive banning sow stalls is implemented.

The Directive 2008/120/EC came into effect on 1 January requiring sows to be kept in groups for most of their pregnancy.

The political decision was initially passed in Europe in 2001 and the European countries have had 12 years to comply with the measures.

The UK was one of the few countries to comply and has been using loose housing systems for over a decade.

A similar animal welfare directive, Directive 1999/74/EC, banning the use of battery cages for laying hens and stipulating the need for cage enrichment came into effect at the start of 2012.

And initially a large number of countries did not comply with the rules.

Now the European Commission is going down the same regulatory lines over the non-implementation of the sow stall ban as it did with the ban on battery cages.

Countries not complying with the directive have two months to reply and come up with a satisfactory response to the formal notice letter.

If the response is found not to be satisfactory, the European Commission will issue a Reasoned Opinion, which gives the countries two months to comply with the directive.

If they still do not comply, the matter is sent to the European Court of Justice.

This process was followed for those countries that failed to implement the laying hens' directive.

A spokesman for the European Commission in Brussels said that the process puts legal pressure on countries to comply.

He said that with regard to the directive for laying hens, the measures had seen the numbers of countries reduced down from their initial high point to 10 when the stage of being sent a Reasoned Opinion was reached.

He said that the countries that will be referred to the Court of Justice should be announced in the next month.

But he added that the number should have fallen even further as the member states fall into line.

He added that this process will be followed for the implementation of the sow stall ban and it is envisaged that the legal pressure will force many of those that have received the formal notice letter to comply.

The commission spokesman said that it takes time to consider the responses and to decide which states need to have further action taken against them.

The Commission said: "Member States which do not fulfil their leg