Christchurch BC may launch an appeal after a High Court judge today refused its challenge to local government reorganisation plans.
The council had claimed that the secretary of state had ‘acted beyond his powers’ in passing the legislation to allow reorganisation to go ahead.
Christchurch leader, Cllr David Flagg, said: ‘We are disappointed by today’s judgement.
‘We have been advised that a number of points set out in the judgement are still arguable in law and therefore we will be responding to the judge on these.
‘Depending on his response we will consider whether an appeal to the Court of Appeal would be appropriate or not.’
The council has repeatedly pointed out that a referendum found 84% of its residents were against the proposal to turn two-tier Dorset into two unitaries.
A statement issued on behalf of the other Dorset councils read: 'We are delighted but unsurprised by today’s judgement.
'A huge amount of work has already been undertaken and we are making excellent progress towards creating the two new councils.
'Christchurch BC has spent a very significant amount of council tax payers’ money in pursuing this legal action.
'The High Court has rejected that challenge and we hope that all Christchurch borough councillors will now accept that judgement, and fully take part in planning for and making decisions about the new council.
'We are optimistic this matter is now behind us, and we can look forward to working together to create the best new local councils we can to protect public services as much as possible, and to secure future growth and prosperity for our areas.'