Legislation to scrap a cash-crisis council and seven others in the same county has been shelved.
It would allow the creation of two unitary authorities in Northamptonshire to replace its troubled county council and the district and borough councils.
The government had already approved the plan, and Parliament was expected to pass it before the election.
But it was put on hold after Labour called for a third unitary council in the county, to serve Northampton only.
A government report in 2018 recommended the scrapping of the Conservative-run county council, which twice banned all but statutory spending.
A draft Structural Change Order confirmed two "shadow authorities" would be set up during a transition period following local elections in May.
Labour-run Corby Borough Council was the only authority in Northamptonshire not to lend its support to the proposals.
The new North Northamptonshire and West Northamptonshire Councils were due to start operating on 1 April 2021 but the position is now uncertain until after the general election on 12 December.
Andrew Lewer, Conservative candidate for Northampton South, said: "The borough council's own figures, based on research they've done, says it's going to cost an extra £750 per year for a Band D house in Northampton South for a purely Northampton-based unitary, rather than going ahead with the very prolonged process we've already had for a more sustainable solution for local services."
Labour candidate for Northampton South, Gareth Eales, said: "Labour will adopt something that was already part of a report by an organisation called Deloitte, which said the three-unitary solution was the more preferable but the local Conservatives and the government opted to ignore it and went with their own preferred option, which would electorally benefit them."
Andrew Simpson, Liberal Democrat candidate for Daventry, said: "We've always said there should be more than just two unitary authorities for Northamptonshire but we've had this imposed on us by the Conservatives and a lot of work has been done to get to this point. So, the question is, can we take it forward and what can we do to quickly get local government back and running?"
The unitary authority model means all council services come under one authority's remit, rather than some the county council providing services such as education, community health and social care, and borough and district councils looking after services including waste collection and planning.
Under the plans, South Northamptonshire, Northampton and Daventry would effectively merge to create West Northamptonshire Council.
A second unitary authority - North Northamptonshire - would cover Corby, East Northamptonshire, Kettering and Wellingborough.
The prospective parliamentary candidates already chosen by their parties include, for Northampton South:
- Andrew Lewer (Conservative)
- Gareth Eales (Labour)
- Jill Hope (Lib Dem)
- Scott Mabbutt (Green)
- James Cotton (Brexit Party)
- Chris Heaton-Harris (Conservative)
- Andrew Simpson (Lib Dem)
- Clare Slater (Green)
- Peter Janusz (Brexit Party)