The new law will ban the use of sow stalls for the majority of a sow’s pregnancy. At the moment, female pigs can spend much of their adult lives in the stalls, where they do not have enough room even to turn around.

The partial ban will create more of a level playing field for British farmers – sow stalls have been banned completely in the UK since 1999 – but new figures obtained by CIWF from the EU Commission suggest they will have to wait even longer than the 13 years they have waited so far.

The UK is expected to be joined in being fully compliant by Sweden, Luxembourg, Lithuania, Ireland, Germany, Estonia, Denmark, The Czech Republic and Bulgaria.

All of the other 17 member states are in varying stages of readiness, with Poland among the worst in terms of the number of farms (2,029) expected to be non-compliant with the law on 1 January, according to CIWF.

Compassion’s Chief Policy Advisor, Peter Stevenson, said: “This should set alarm bells ringing at the Commission and the 17 member states that are not going to comply with the ban. They need to get hold of the situation very quickly to stop this important step for animal welfare becoming a farce.

“It’s unacceptable for so many countries to be behind schedule when they have known for a long time that these rules would be coming into force on 1 January. They need to take action now, both for the welfare of millions of pigs and to create a fairer market for UK farmers.

“The Commission needs to make it very clear that there will be significant consequences if they are still not in line come 2013.“

With some countries unable to provide detailed statistics, among them Belgium, France and Portugal, Compassion fears implementation will prove difficult.

The barren battery cage ban for laying hens came into force in January this year. Twelve member states are still to comply with the new rules, which outlaw battery cages.