The EU competition commissioner Neelie Kroes has threatened legal action unless Europe's energy majors do more to open up their markets in line with EU liberalization legislation.

Ms Kroes says that a new interim report drafted by Brussels authorities shows some serious flaws in the functioning of the continent’s gas and electricity markets.

I am determined to use competition law to protect European industry and consumers, the commissioner told the press. However, while the EU did not rule out the possibility of further legislation being required to drive greater market opening, definitive proposals for action are unlikely to be unveiled until more detailed country-by-country research has been collated.

The interim report pointed to Greece, Spain and Ireland as markets that were in particular need of further action to stimulate competition. The report also suggests that too many member states have done the bare minimum to enforce existing competition rules, leaving former monopoly players with an unhealthy position of power in many European markets.

Member states need to quickly and fully implement the gas and electricity directives not only in letter but also in spirit, the EU energy commissioner Andris Piebalgs added.