An application to build a new nuclear power station has been accepted for examination by the planning inspectorate.
Plans for the Sizewell C plant on the Suffolk coast were put forward by EDF Energy after being mooted 10 years ago.
The acceptance means an examining authority will now be appointed to scrutinise the application, with the government having final decision.
Stop Sizewell C (SSC) group said it will continue to fight the application.
EDF Energy said in a statement: "The decision means the Inspectorate is satisfied that the eight years of public consultation by the project was conducted properly and that full examination of the proposals can now take place."
But Alison Downes from SSC said the "quality of EDF's consultations failed to provide required information".
She added EDF "had not been transparent in its disclosures of environmental assessment or transport strategy" nor the plant's impact on the local area.
Concerns about effective scrutiny of pre-application proposals during the lockdown restrictions was supported in letters from local MP Dr Dan Poulter and Suffolk County Council.
In a joint statement on Wednesday Suffolk County Council and East Suffolk Council said:
"The lack of a comprehensive set of documents up to this point has compromised the engagement that has taken place, and the Councils do not feel they have been able to complete their pre-application work with the Applicant (EDF Energy) to the extent set out by the Planning Act 2008,"
EDF Energy said a copy of the full planning application and supporting documents would become available on the Planning Inspectorate website.