Ms Fitzgerald said it was made “very clear” to the 17 gardaí currently waiting to be promoted that the panels they were on would “expire” when the authority took over.
The gardaí will then have to reapply for the posts under the authority.
The Tánaiste was speaking yesterday at a passing-out ceremony for 145 gardaí at Templemore Training College.
The Garda Commissioner, Nóirín O’Sullivan, said there were at least eight critical vacancies at senior level and they needed to be filled immediately.
Ms Fitzgerald refused to state whether there would be any positions filled before the regulations are brought in by year-end, transferring the power to the Policing Authority.
“I’m going to have a discussion first with the commissioner,” she said. “I’ll be examining the critical vacancies that are there and I’ll be considering, and the Government will be considering, the precise timeframe.”
Some 17 gardaí were put on a promotion list in July. It is thought the last time a promotion list expired before it was fully executed was 1987.
Referring to the 17 applicants, Ms Fitzgerald said: “Anyone who applied knew the panels were going to expire and it was made very clear that once the transfer took place that those panels would expire.”
Asked why she had not filled the critical vacancies, Ms Fitzgerald said: “There is no reluctance to fill critical vacancies. No one has invested more in An Garda Síochána than myself.
“Up to July, I made 32 appointments. I filled all the vacancies there were in An Garda Síochána.
“Three vacancies arose in September and I was informed, today, there are a further five vacancies.”
She said there were eight critical vacancies under the Employee Control Framework, set in 2012.
Ms O’Sullivan referred to remarks she made at the Policing Authority last June, in which she called for the “immediate appointment” of 46 senior officers, describing them as “critical vacancies”.
The Government subsequently agreed to 28 of those 46 appointments.
“I remain of that view,” said Ms O’Sullivan. “We are working with the Department of Justice and the Policing Authority to make sure those vacancies are filled as soon as possible.”
Ms O’Sullivan said there were operational and strategic changes in the organisation since the framework was created, in 2012.
She said the critical vacancies included one assistant commissioner, two chief superintendents, and five superintendents, which, when filled, would have knock-on effects.