Sinn Féin, Labour, and the Social Democrats said that the new documents on advice given to her in 2015 show she clearly knew — even though the Tánaiste has denied this.
The new documents released by the Department of Justice show she was made aware a second time in July 2015 of a potential Garda strategy to undermine Sgt Maurice.
This was several weeks after a first email in May 2015 notifying her of the Garda plan at an inquiry.
The correspondence reveals that assistant secretary Ken O’Leary also told Ms Fitzgerald to stress her belief “that Sgt McCabe is a valued member of the force”.
It also confirms that the Department of Justice liaised with the former Garda commissioner, Nóirín O’Sullivan, and the Garda press office on these matters. Gardaí had received a similar media query.
Sinn Féin’s justice spokesman, Donnchadh Ó Laoghaire, said: “These documents are further evidence of the Tánaiste’s failings in addressing very serious issue, and her failure to protect Maurice McCabe from an appalling smear.
“The case for the defence for Tánaiste Frances Fitzgerald has been unravelling for days. It has now collapsed. She has tried to say there was nothing she could do anyway; this has been comprehensively rebutted.”
Labour leader Brendan Howlin also said the Tánaiste must now resign. Her position was “untenable”, he stressed.
“It is beyond explanation how she could tell Dáil she had no knowledge of these matters now,” said Mr Howlin.
The Social Democrats also said the Tánaiste’s position was untenable.
“Whatever about a minister not recalling an issue being raised once in an email, this departmental trawl shows that both the minister and her officials were informed in another two further emails, and in considerable detail, about media inquiries about the legal strategy adopted by the Garda commissioner,” said co-leader Róisín Shortall.
“How can the Tánaiste continue to credibly maintain that she wasn’t aware of the legal strategy, despite her officials and her special advisers being included in the email chain released tonight?”