Ballymena Councillor Declan O’Loan is accusing Mid and East Antrim Council of "massaging the figures".
The allegation is over what they spent on their Somme Centenary Festival this summer.
Council staged a gala concert in Carrickfergus featuring singer Aled Jones at its centrepiece.
The original estimated cost of the event was £60 000, but Council's final expenditure was £63 422.