So far this year, the Netherlands has exported more gas than it has imported, new figures from the national statistics office CBS show. It is the first time since the 1950s that gas imports have outstripped exports for several successive months.

Imports hit a record five billion cubic metres in September, the CBS said. Most of the gas comes from Norway.

Imported gas was used primarily to generate electricity in heavy industry but is now also being used in private homes.

The rise in imports is due to the decision to slash production in Groningen, to head of the risk of earthquakes.