A unitary authority which has forecast saving taxpayers’ £5m in its first year is facing criticism that the lower costs are due to falling electricity prices while it has failed to deliver promised efficiencies from unifying eight councils.

Opposition leaders on North Yorkshire Council have questioned a statement issued by authority claiming millions of pounds in taxpayers’ money is expected to be saved in its first year, realising “the benefits of the biggest overhaul of local democracy in nearly 50 years”.

The authority, which leadership of which justified unifying the county’s seven district and borough councils with its county council largely on the basis of the savings that could be achieved, issued the 800-word statement ahead of the first quarterly financial report for the new council being published.

The council has claimed by joining up services and maximising spending power, North Yorkshire Council will eventually recoup between £30m and £70m annually.

The £5m savings forecast represents an increase in savings from the authority’s announcement in June that it had saved taxpayers £3.8m a year in the transition from eight councils to one by cutting the roles of 24 senior managers.

The financial report states almost £4m savings are due to contractual electrcity prices for street lighting being agreed at much lower rates.

Nevertheless, the council’s statement underlined the “benefits which have been brought about by merging eight councils into one authority”.

The council’s executive member for finance, Councillor Gareth Dadd, who is also the authority’s deputy leader, said: “We can already see the benefits of creating one single council for North Yorkshire with the chance to make millions of pounds of savings in the first year alone.

“We will make a concerted effort, though, to build on the work that has already been undertaken to make sure that every pound of taxpayers’ money is spent wisely and used as effectively as possible to deliver key services across the county.”

However, Independent group leader Councillor Stuart Parsons said the council’s planning service was “refusing to service”, waste collection changes had been made without any consideration to staff or the public, the highways team was “delaying jobs they are supposed to be carrying out”, and that there was a critical shortage of customer care staff.

He said: “The money is being saved by not delivering services. Residents are not getting responses to their questions from the council, so they come to me, but I am meeting with the same reticence to say hello. What used to take one or two emails is now taking six or seven.”

Councillor Steve Shaw Wright, leader of the authority’s Labour group, said it had become apparent services would see further cuts, “with none of the benefits of this great new unitary appearing to make any difference whatsoever”.

He said: “It is frightening for some people. You almost need to be in the next door to death category to get sort of service. The mild and moderate have gone out of the window and almost the severe are heading that way as well.”

Liberal Democrat group leader Councillor Bryn Griffiths highlighted concerns over the authority’s planning service, adding that getting the council’s management structure changed in a short space of time had proved “difficult” and the authority may have underestimated the amount of work needed to  reassign the workforce.