The Department of Justice has been told that senior gardaí are dealing with "unsustainable workloads" posing serious "health and safety" risks because critical vacancies are not being filled.
Former Garda Commissioner Nóirín O'Sullivan wrote to the Department in April of this year to say there was a significant governance risk to the force caused by the doubling up of portfolios among Assistant Commissioners.
Her colleague, the now acting Garda Commissioner Donall Ó Cualáin, raised similar concerns on behalf of superintendents.
Documents released to RTÉ under the Freedom of Information Act show Nóirín O'Sullivan informed the Department of Justice that the compliance, responsibility and accountability demands on the force had increased.
"In that environment the risk of the existing Assistant Commissioner team carrying extraordinarily large portfolios is not sustainable and poses significant governance risk," she said.
"The 24x7x365 nature of the responsibility is onerous for an individual holding one brief but almost impossible to hold more than one portfolio over a prolonged period."
She said there were "health and safety" concerns around the workload of gardaí at the highest level.
She said there were "significant organisational leadership gaps" which should be explored by the Government and the Policing Authority.
The former commissioner said an increase in the number of new probationer gardaí must also be met with a consequential expansion in numbers at supervisory and management levels.
In recent months the force has been permitted to recruit more senior officers to fill critical gaps.
However at Assistant Commissioner level there are still a number of very senior gardaí doubling up on portfolios.
Those include the Assistant Commissioner for South Eastern Region who has temporary responsibility for Governance and Accountability.
The Assistant Commissioner for the Dublin Metropolitan Region continues to have additional responsibility for Community Engagement and Public Safety.
And the Assistant Commissioner for the Western Region also holds responsibility for Corporate Services and Executive Support.
The number of senior officers which can be appointed to the gardaí is limited under a government policy known as the "Employment Control Framework".
These limits are not set based on policing priorities, but on cost considerations.
In a another letter send to both the Policing Authority and the Department of Justice in July, Ms O'Sullivan said "given the current realities and demands it is simply not possible to continue to operate within the current Employee Framework" which she said was imposed in 2012 in response to stringent austerity measures at a time when the force was to reduce to 11,500.
