The practice of gardai receiving allowances for carrying out non-essential work on public holidays represents a "culture of entitlement", according to the force's own auditors.
The hard-hitting criticism of the practice is contained in a report by the Garda Internal Audit Service (GIAS), which estimated that the cost of allowances for staff working at Garda HQ over 12 public holidays was adding €800,000 to the garda pay bill each year. It found many claimants were not engaged in "high visibility" duties.
"Allowances are not intended to be used as supplemental income," the auditors observed.
The allowance can be equal to two or three times basic pay, depending on rank and whether or not the public holiday is a rostered rest day.
Based on its findings, the GIAS recommended non-essential work should not be necessary or undertaken as a matter of routine on public holidays in future.
Garda auditors said they could only provide "limited assurance" that the payment of public holiday allowances to gardai for non-essential duties was efficient and represented good value for money, especially as some would also be entitled to an extra day off work.
They questioned if the duties performed by such gardai were necessary and effective for the prevention of crime or contributing to visible policing.
The report, which was released under freedom of information legislation, examined the payment of €201,000 in allowances to gardai based in Garda HQ for working on three public holidays over Christmas and New Year in 2018/19.
"While this level of cost is not material in the context of the overall Garda Vote (budget), it demonstrates the lack of prudent financial accountability and oversight of public monies by managers and supervisors," the audit observed.
It added: "It suggests a culture of 'entitlement' versus the public good, which is not true to the ethical values and professionalism being promoted in the organisation."
An Garda Siochana refused to release details of how many of the 587 gardai based in 27 sections at Garda HQ worked on public holidays on security grounds.
The total spend on public holiday allowances over the Christmas period for the entire 13,800-strong force was €4.95m, with around 52pc of all gardai rostered to work on Christmas Day, St Stephen's Day and New Year's Day.
The GIAS said a high attendance rate by gardai at Garda HQ over the three public holidays at Christmas was questionable and the duties performed on the public holidays required justification. It claimed senior management needed to put significant focus on reviewing the necessity for gardai to perform non-essential duties on Sundays and public holidays.
Garda attached to various divisions and districts told auditors that rosters could not be changed.
However, the GIAS pointed out that the Westmanstown Agreement on working hours allowed for flexibility and adjustments to rosters in line with policing needs. The GIAS said it believed that management had not empowered chief superintendents and superintendents to implement "a more agile approach" to roster planning.