You might be referring to this:
https://www.bristol247.com/news-and-features/news/leaked-letter-reveals-power-struggle-between-regions-leaders/A leaked letter penned by the region’s four council leaders has revealed a power struggle with metro mayor Dan Norris, with claims that recent decisions may be “unlawful”.
The correspondence, signed by the elected heads of Bristol, South Gloucestershire, Bath & North East Somerset and North Somerset councils, accused Norris of exercising a power of veto at last month’s West of England joint committee that he is not entitled to.
An accompanying note agreed by all four local authorities’ monitoring officers, who provide legal advice, says this would “arguably amount to maladministration” and that the decisions could even be challenged in court because they went beyond the committee’s authority.