A cross-party committee called for greater transparency around the formula used to allocate funding to Welsh councils amid concerns about unfairness.

Mark Isherwood, who chairs the Senedd public accounts committee, raised a warning from Aberystwyth town council that the formula disproportionately disadvantages Ceredigion.

In a letter to the committee, Will Rowlands, the town council’s clerk, called for fair funding that adequately reflects the unique challenges in rural, less densely populated areas.

He wrote: “The formula, as it stands, has resulted in a significantly lower percentage of funding for our county, which is detrimental to the economic, cultural and educational wellbeing of our communities.”

Mr Rowlands raised concerns about a long-term risk of declining public services and infrastructure if the Welsh Government’s funding formula remains unchanged.

Mr Isherwood called for independent oversight, warning “turkeys don’t vote for Christmas”.

He said: “The winners are not going to want to sacrifice their position, metaphoric winners, I don’t mean they’re rolling in money but those who do better  … to those that do less well.”

During a meeting on November 6, the Conservative cautioned that Ynys Môn, which has one of the lowest levels of prosperity per head, also has one of the lowest settlements.

Mr Isherwood added that Conwy, which has an older population, is one of the worst funded and he raised Audit Wales concerns about Flintshire council being at risk of bankruptcy.

He explained that ministers maintain the formula is reviewed annually, with the input of the Welsh Local Government Association (WLGA), the national voice of Wales’ 22 councils.

Labour’s Mike Hedges urged Welsh ministers to publish more detailed information, so people can judge the fairness of funding settlements.

Adam Price echoed calls for greater transparency to aid scrutiny and public discussion, suggesting Audit Wales or another independent body could look into the formula.

Adrian Crompton, the auditor general, told the committee Audit Wales plans to publish a report on financial sustainability of councils in the next month.

Mr Crompton said he would be nervous about reviewing the formula because it would stray into policy questions but he agreed about the need for transparency.