More than 100,000 people have responded to a postal vote on proposals to create a unitary authority in County Durham.
The region's seven district councils sent ballot forms to the 400,000 registered voters asking if they support the plans.
In March, the government shortlisted Durham County Council's bid to replace the districts with a single authority.
The districts say the vote is "an attempt to let local people have their say". Results are expected next week.
The councils had submitted a "Pathfinder to Unitary" bid, which called on several development stages and improvement initiatives leading eventually to unitary status.
But this was rejected in March when the Department of Communities and Local Government said it would only consider the county council's unitary proposal.
The referendum has been organised by the local authorities in Chester-le-Street, Derwentside, Easington, Sedgefield, Teesdale, Wear Valley and Durham City.
A final decision on whether the county council's unitary bid has been successful will be made in July.