A department spokesperson last night refused to be drawn on what action Ms Fitzgerald will take if a widely expected commission of investigation is opened into the controversy.

Last October, retired High Court judge Iarfhlaith O’Neill was asked to investigate claims from Superintendent David Taylor that he and others had been told by senior garda management to orchestrate a campaign to undermine whistleblower Superintendent Maurice McCabe and others.

The claims, which Ms O’Sullivan and other senior managers have rejected, relate to repeated leaks of rumours surrounding Sgt McCabe’s personal and professional life, an issue Sgt Taylor said he was asked to organise as then head of the garda press office.

In early December, Mr Justice O Neill provided a report on the controversy to Ms Fitzgerald which is understood to have recommended a commission of investigation be set up to examine the matter further.

However, while the report has been in Ms Fitzgerald’s possession for almost two months, it has yet to be published due to ongoing discussions with the attorney general, sparking speculation that it has recommended a commission of investigation into the claims.

In the Dáil on Tuesday, Independents4Change TD Mick Wallace said Government will be “making a mockery” of Sgt McCabe and others if it allows Ms O Sullivan to remain in her position while a commission of investigation takes place due to conflict of interest concerns.

Such an investigation would be likely to take a number of years, effectively meaning Ms O Sullivan may not be in a position to return to her role if she is asked to step aside.

However, asked about whether Ms Fitzgerald will seek the move in the event of a commission of investigation being established in the coming weeks, as has been widely suggested, the Department of Justice refused to say what may occur.

In a statement to the Irish Examiner, the department said Ms Fitzgerald “is engaged in the process of preparing proposals arising from it [the report] with a view to their submission to Government as soon as possible”.

The department said Ms Fitzgerald “is not in a position to make any further comment on the report until that process has been concluded”, and that it would “not be appropriate to make any comment on [Mr Justice O Neill’s findings] other than to make the general point that the Tánaiste has consistently expressed confidence in the garda commissioner”.

While Ms Fitzgerald’s decision to continue expressing confidence in Ms O Sullivan underlines the Government’s official support for the Garda Commissioner, the long delay in publishing a report given to her at the start of December has led to mounting speculation that a commission of investigation is set to be launched.