Environmentalist groups in Germany and the Netherlands are challenging plans for a new gas field in the North Sea, a German non-profit organization said on July 15, possibly complicating Europe's hunt for alternatives to Russian fuel.

Environmental Action Germany (DUH) said it had filed the lawsuit with the Court of Justice in The Hague together with Dutch organization Mobilisation for the Environment (MOB) and a citizens' initiative from the coastal region of East Frisia.

Privately-owned Dutch company ONE-Dyas has been given the go-ahead by Dutch authorities to develop its N05-A gas field in the North Sea, straddling German and Dutch waters, with gas production also planned at surrounding fields.

The platform will run entirely on wind energy, according to the company.

It hopes to start delivering natural gas to Dutch and German households by the end of 2024, with an expected potential of around 13 Bcm of gas.

"The construction of a new platform in the North Sea will create a new infrastructure that will increase our long-term dependence on fossil energy. This is not compatible with climate targets," said DUH chief Sascha Mueller-Kraenner.

The DUH also said the site was close to the Wadden Sea, a UNESCO World Heritage Site and the largest unbroken system of intertidal sand and mud flats in the world.

The German islands of Juist and Borkum have jointly filed another lawsuit against the planned gas exploration, according to the pressure group.

Neither of the islands' administrations was immediately available for comment. ONE-Dyas did not immediately respond to an emailed request for comment.