How dependent is Europe upon Russian energy sources?
5 May 2014 Last updated at 13:57 BST
With relations worsening between Ukraine and Russia, ministers are investigating ways that European countries can become less dependent upon Russian energy sources.
At present, half of all Europe's gas comes from Russia, with the main pipelines passing through Ukraine.
European governments are concerned that as tensions continue, Russia could cut off this supply.
Jeremy Howell reports.