The battle for control of Norwich's public services exploded into a fresh row yesterday, with City Hall accused of keeping the public in the dark about its financial plans after last-minute revelations about how its £18m home rule scheme will be paid for.

The battle for control of Norwich's public services exploded into a fresh row yesterday, with City Hall accused of keeping the public in the dark about its financial plans after last-minute revelations about how its £18m home rule scheme will be paid for.

Ministers yesterday closed their consultation on plans to allow Norwich and Ipswich to become go-it-alone unitary authorities - seizing powers from county councils to run services such as schools and care for the elderly.

Yet as the deadline passed, City Hall unveiled changes to its bid - claiming it could meet the £18m bill for home rule in half the time - sparking fury among opponents that they had been denied the chance to scrutinise the final proposals.

Norwich was accused of taking an “almighty risk” with public services and urged to come clean on what sell-offs and cutbacks would be needed to make the plans work.

The authority said it would have announced the changes sooner but officers had been working till the last minute on the plans because it had not been provided with the facts it needed from the county council.

But County Hall strenuously denied it had held back information and claimed the city had manipulated the consultation process because its case did not stand detailed scrutiny.

With Treasury number crunchers said to be in the ascendant when the final decision is made on July 25, the city council believes it has found a way of reducing the time needed to pay the transitional costs to switch to a unitary from 4.2 years to 2.6 years.

And it says it will have access to about £13m over five years, based on yields from the county's property and asset portfolio - up £3m from its original forecasts, which it says will help bring down overall costs by more than £5m.

It also envisages getting its hands on some of the £1m annual dividends raised by the county's offshoot firm Norfolk Property Services.

The council is also looking at switching from elections every year to whole-council polls and is to set up a special scrutiny committee to determine how often elections to a new council should be held.

Norwich council leader Steve Morphew said improvements in the city's finances meant that reserves for a new unitary would increase from a predicted minimum of £1.3m to £2.9m.

“We have reduced the cost and boosted the savings,” he said. “It's a refinement to the original bid but there are some significant elements to it.

“One of the problems with the original bid is that we had made many assumptions but we didn't have the information we needed from the county council.”

Critics pointed out that some elements of the bid were based on one off “fortuitous savings” while the latest forecasts have not been subject to independent analysis.

And with spending on “demand-led” services for vulnerable children and adults notoriously unpredictable, County Hall believed the case will not stack up, and with a new authority forbidden from increasing council tax to pay for services, sell-offs and cuts will have to follow.

Daniel Cox, leader of Norfolk County Council said he was concerned the city had not shared its latest calculations during consultation so that others could publicly scrutinise or verify their accuracy.

“A considerable risk appears to have turned into an almighty one,” he said. “Norwich seems to have conjured up extra millions to make things add up on paper, presumably to persuade a sceptical Treasury that it could pay off its set up costs quicker. Doing that is one thing, making it happen without running into massive financial problems and damaging public services is quite another.” “Which buildings would close and where would they put all the people who occupy them,” he added. “The evidence shows that the bid doesn't meet the government's five criteria for approval and that most people and stakeholders are against it. If the decision is made on evidence, and we have been repeatedly assured that it will, then the Norwich bid should, and will fall.

Simon Woodbridge, leader of Broadland district council, added: “They are being hugely disingenuous. They are manipulating quite deliberately the way in which they are presenting information.

“There is a huge amount of wishful thinking on Norwich's part and it's really time we put this to bed,” he said. “Norfolk people aren't stupid they want to see how this can be done, and all they have got is rhetoric.”