Variations of both plans that split Amber Valley up between north and south have also been put forward.
However the public has not backed any of the proposals. A recent consultation found the idea of merging councils in the county had failed to win widespread support.
A final submission to government will be made on 28 November for a decision from the Ministry of Housing, Communities and Local Government.
The existing councils would be scrapped and replaced with larger authorities in 2028.
Reform UK’s late switch to a radical alternative will complicate that decision even though the proposal goes against much of the guidance councils were given on how to make their plans.
Alan Graves admitted the plan for a unified Derbyshire had elements that were different from what the government wanted but said he was offering ministers a choice.
“There is a solution for them to look at,” he said. “There’s a serious solution that will solve a lot of problems and I actually think they will give that some serious consideration.”
