Environmental group Zero on Monday complained that documents in public hearing in Portugal concerning Spain's nuclear waste deposit plan don't present anything new.
"It was a relative surprise that the documents that are available at this moment, for public hearing in Portugal, don't bring anything new," Carla Graca from Zero told Portuguese Lusa News Agency.
The Portuguese Agency for the Environment (PAE) published documents on the nuclear deposit plan on Monday.
Graca added that there was still no assessment of cross-border impacts.
Portugal sent a complaint to the European Commission in January regarding Spain's decision to build a nuclear waste deposit in Almaraz, about 100 km east of Portugal's border.
Portugal said in the complaint that an assessment on the impact the waste facility will have on Portugal should have been carried out.
Portugal last month reached an agreement with Spain to withdraw the complaint regarding the nuclear waste deposit plan, but said it didn't mean a new complaint wouldn't be presented to Europe in future.
Spain said it committed to not issuing any license or authorization regarding the operations of the warehouse.
But Portugal's Minister of Foreign Affairs Augusto Santos Silva said Portugal would "not abdicate from presenting another complaint if joint work in the next two months leads to inconclusive results".