In 2020 the UK energy company Ascent Resources brought an ISDS case against the Slovenian state for requiring it conduct an environmental impact assessment of a proposed fracking project. The requirement came after members of the nearby Petišovci community petitioned the Slovenian authorities, concerned about the impact the project would have on a nearby water source.

Ascent told Sky News that the Slovenian government's position was “arbitrary and unreasonable” and was suing for €120 million in compensation using the Energy Charter Treaty's ISDS clause.

In January 2022 Slovenia backed down, passing a new law allowing limited fracking. Friends of the Earth Slovenia said: “Petišovci fracking project clearly shows how energy companies are using the Energy Charter Treaty to extort governments and demand special treatment. Instead of performing the needed impact assessment, Ascent Resources decided to sue Slovenia for more than a 100 million euros. This is simply unacceptable; governments need to leave the ECT and protect our environment”.