The Ceann Comhairle risks being hit by a motion of no confidence after becoming embroiled in a bitter constitutional row about the independence of his office.
Sean Barrett faces the humiliating prospect of a motion going before the Dáil next week as the Opposition demand he withdraw accusations that his position is being undermined, and Fianna Fáil and Sinn Féin are "out to get" him.
Certain Government ministers are furious over Mr Barrett's controversial decision to block a Dáil debate on a motion to establish a commission to investigate garda allegations of malpractice in the force.
Two separate Fine Gael ministers last night said they believe Mr Barrett's standing within the party has been "damaged".
The Ceann Comhairle has also been asked to explain his actions by Government chief whip Paul Kehoe.
The alleged malpractice, which was raised by garda whistleblower Maurice McCabe, formed part of the controversial Guerin report which led to the resignation of former justice minister Alan Shatter.
But the decision to call off the debate is being openly criticised by both Government and opposition figures after it emerged that Mr Shatter wrote to Mr Barrett asking him to do so.
Mr Shatter claimed any such debate could impinge on his ongoing legal battle with Mr Guerin, which is currently before the High Court.
Speaking to the Irish Independent last night, he said: "I hope at a later stage to be able to publicly address all matters of relevance that have arisen, including the vital public interest in ensuring that the constitutional position and role of the courts is fully respected by Government and the House of the Oireachtas."
The move to cancel the debate, which prompted a Dáil walkout by the Opposition, has left the Ceann Comhairle open to allegations of being influenced by the letter from Mr Shatter's solicitors.
Yesterday, Mr Barrett angrily insisted he did not "bow to pressure" from Mr Shatter.
He said he cancelled the debate to avoid the possibility of a High Court action from Mr Shatter delaying the investigation into Sgt McCabe's claims.
Sinn Féin TD Padraig Maclochlainn suggested a motion of no confidence could be brought against Mr Barrett.
A spokesman for Fianna Fáil leader Micheál Martin said the accusation that the party was targeting the Ceann Comhairle must be withdrawn if Mr Barrett "wants to retain our confidence".