More than £600,000 has been spent so far on Norwich's bid to gain unitary authority status allowing it to run a full range of council services.
If Norwich becomes unitary it would gain powers over education
However, part of the bill must be paid by neighbouring authorities which are fighting to maintain the status quo.
The spending figure comes from a Freedom of Information Act request by North Norfolk MP Norman Lamb who said the money could have been better spent.
Norfolk regretted the cost, but Norwich said it was money well spent.
Mr Lamb also said the money could have been better spent on services to benefit the people of Norfolk and Norwich.
Details show Norfolk County Council's bill to date has totalled £309,669, which is larger than the city council's £297,494 spent on its bid so far.
Mr Lamb said he put in a Freedom of Information Act search because he was concerned at the level of spending and the impact a unitary council for Norwich would have on the rest of the county.
"It's a hell of a lot of money and one's inevitably left thinking what services could be provided for that cost," he said.
Daniel Cox, Leader of Norfolk County Council, said the council had regretted having to spend any money responding to Norwich City Council's bid for unitary status.
"We see no appetite for such a proposal among the public, or indeed the majority of stakeholders.
Money well spent
"Norfolk County Council has been forced to divert staff from their normal duties to do this work."
Laura McGillivray, chief executive at Norwich City Council, said so far it was money well spent.
"Our spending has gone on a bid project manager, surveys on stakeholder attitudes and consultants to help us prepare for taking over responsibilities we don't have at present such as adult social care and children's services."