Tesla is making changes to an application that must be approved before it can start production at its German car plant, a move that opens up the risk of more delay.
The company aims to incorporate improvements to the plant and also add a facility to make battery cells, Brandenburg's state environment ministry said Tuesday, adding that it expects the changes to necessitate another round of public consultation.
"Since there are no further details about the nature and scope of the planned changes, statements on the process and the time it will take to take a final decision can only be made at a later stage," the ministry said.
Public opposition already was testing the patience of CEO Officer Elon Musk, who has questioned for months why environmental groups have raised objections to Tesla's plans.
On Monday, the automaker said vehicle production at the site near Berlin is on track for late 2021, contrasting with a July timetable communicated just a few weeks ago.
Tesla has said up to 500,000 Model Y cars could be produced at the site annually once it is completed.
Tesla recently asked for permission to have crews work 24 hours a day during the week to install ventilation stacks at the facility, in addition to carrying out interior construction work on Sundays, according to Brandenburg's environment ministry.
The plant in the small town of Gruenheide is supposed to underpin Musk's efforts to better compete with Volkswagen Group, Daimler and BMW in Europe.
Local authorities had hoped to approve the factory as early as last summer, but lawsuits from environmental groups concerned about water use and threats to local wildlife delayed the project.
The pandemic also pushed back the process by several months.
Earlier this month, Tesla criticized the lengthy process of securing final approval for the plant.
German authorities also temporarily suspended work at the site recently after Tesla was found to have laid waste-water pipes without a permit, Brandenburg's environment ministry said earlier Tuesday.
The ministry imposed a more than two-week work freeze and is now considering fining Tesla, it said by email, confirming an earlier report from broadcaster ZDF and Business Insider.
Reuters contributed to this report