A KEY watchdog has asked for greater clarity over Worcester City Council's finances - firing a warning over "back of the fag packet" claims.
The city's audit committee, a powerful body which probes public spending, says too many facts and figures coming out of the Guildhall are not examined closely enough.
It says many policies to come out of the council are accepted without claims from staff about the financial pros and cons of each one being scrutinised properly.
The committee, which meets around six times a year, has asked the council to give it thorough details on how any type of "modelling" is arrived at in the future.
It follows a decision back in November by the council's Labour leadership to turn its back on food waste bin collections due to the costs.
At the time, staff said it would cost £1 million to launch extra bin collections for the city's 40,000 households and around £544,000 in yearly running costs.
But details of how the city council arrived at that figure was never probed or made public.
Councillor Andy Roberts, who chairs the audit committee, said: "This committee ought to have more reassurances on how modelling is done.
"When the council works out a figure we ought to know what was put into it to get the figure, and how does it all work."
He said councillors get reports containing figures of hundreds of thousands of pounds, but the committee should make sure it isn't "back of the fag packet stuff".
His comments were taken on board by officers, who said things would change in the future.
At the time of the food waste collections being pushed aside, Worcester Green Party insisted the figures needed greater clarity.
Green Councillor Neil Laurenson said it was a "missed opportunity".
The audit committee, meanwhile, has accepted assurances the city's housing benefit and council tax transactions are on track.
Every year the data must be independently verified and for the 2012/13 financial year, out of £77 million worth of transactions, a discrepancy of £799 was flagged up by Grant Thornton.
When the amounts do not add up the Government has the power to ask councils to do an audit trail through the rest of the books to see if there are anomalies elsewhere.
During the committee meeting Lesley Meagher, corporate finance director, insisted it was "very unlikely" the council will get that request.
"It's such a small amount I don't think the DWP (Department for Work and Pensions) will do anything, they'll have bigger cases to look at," she said.