Reorganisation of seven councils could cost £18m

County councils, such as Cambridgeshire, would no longer exist under the new plans

The cost of creating unitary councils across Cambridgeshire and Peterborough could be more than £18m, a chief executive has said.

Stephen Moir, in charge of Cambridgeshire County Council, said the sum would have to be "consumed" by the existing councils.

In February, Jim McMahon, the local government minister, wrote to council leaders asking them to create a new "simpler" local government structure.

Cambridgeshire currently has a two-tier system of local government, with a county council and five smaller district and city councils. Peterborough runs as a city-wide unitary authority.

Peterborough already has a unitary authority, but has been asked to talk to its neighbouring council areas about its plans

The letter asks the leaders of all seven councils to submit their initial plans by 28 March, with a full submission by 28 November.

The area already has a combined authority with a mayor.

Mr Moir told councillors at a strategy, resources and performance committee meeting that the government had been "very clear" councils would be expected to "consume the costs of local government reorganisation".

He anticipated it would cost "at least £18.6m", said the Local Democracy Reporting Service.

Conservative Fenland District councillor Chris Boden said the figure was "horrifying" and asked where it would be spent.

The county council said it had agreed to set aside up to £1m to help pay for some of the extra work being done on the reorganisation.

Mr Moir said: "We are having to look at our own reserves to partly support that, in addition to the extensive use of existing county council staff.

"I need to be able to make sure we get the balance right, so business as usual services do not suffer as a consequence of having to respond to the government's invitation."

In a draft response from six council leaders, it states that they were "considering different unitary scenarios".