Christchurch BC has warned it could take legal action if the Government forces it to merge with Bournemouth and Poole councils.
The council is opposing plans to create two new unitary authorities in Dorset.
Instead, it is calling for Bournemouth and Poole join together to form a single unitary authority, wih the rest of Dorset remaining as a two-tier structure.
The council is also requesting additional time to fully work up its proposal after a referendum found 84% of residents were against the merger plans.
Christchurch leader, Cllr David Flagg, said: ‘Christchurch BC wishes to retain our sovereignty and we believe that retaining the existing two-tier structure in Dorset presents a credible alternative that the Secretary of State will take time to consider.
‘With Bournemouth and Poole already sharing a number of corporate services, the suggestion of them becoming a single unitary authority would take this one step further and our representation offers estimated savings at the same level as those of the Future Dorset model.’
Christchurch has approved a £15,000 budget to take legal advice and initiate proceedings if Mr Javid approves the Future Dorset submission.