The twists and turns in the events that have led to today’s controversy over Sean Barrett are many and complicated.

But this afternoon the Ceann Comhairle is now facing the prospect of having to resign, unless he withdraws allegations that opposition parties are trying to undermine him.

The outcry relates to Barrett’s handling of an attempt by Alan Shatter to block a debate on a Commission of Inquiry investigating his own handling of allegations of Garda malpractice.

The ex-minister wrote to Barrett trying to have a two-day debate called off, because it might interfere with a High Court case he’s taking against the findings of a report by Sean Guerin – which in turn investigated Shatter’s own alleged mishandling of alleged Garda malpractice, as embodied in the whistleblowing allegations of Garda Sgt Maurice McCabe.

Confused? Quite possibly. So here’s our bullet-point guide on how we got this far.

• Sgt Maurice McCabe is a serving Garda sergeant – perhaps better known for his allegations about widespread corruption in the handling of the penalty points system. Earlier in his career he was stationed in Bailieboro, Co Cavan.
• While there, he became aware of several instances of alleged crimes which were either ignored, or mishandled, by the Gardaí responsible for dealing with them.
• McCabe tried to raise these concerns within the force, but was unhappy with the response.
• He then tried to raise them with the Minister for Justice and Equality, Alan Shatter, but was again unhappy with the response.
• He then began to raise the concerns with members of the Dáil, including Fianna Fáil leader Micheál Martin, who said a sample of ten cases were particularly worrysome and brought them to the attention of Taoiseach Enda Kenny.
• Kenny believed the issues serious enough to warrant immediate scrutiny, and Cabinet agreed to set up a ‘scoping exercise’ where an experienced criminal lawyer, Sean Guerin SC, would determine if there were grounds for a full Commission of Inquiry.
• Guerin’s terms of reference included a specific request that Guerin “interview Sgt Maurice McCabe and any other such person as may be considered necessary and capable of providing relevant and material assistance”.
• Two months later, in early May, Guerin returned his report – which was damning of how McCabe’s allegations were handled by many, including Alan Shatter. In particular, Guerin said that in some instances, Shatter had referred complaints about the actions of the Garda Commissioner to... the Garda Commissioner himself, and that Shatter was happy to accept whatever explanation he was given without further scrutiny.
• Shatter resigned as Minister for Justice and Equality, ostensibly because he did not want to pose a distraction to Fine Gael in the run-up to the nearby Local and European elections. In his resignation letter, however, he complained that Guerin had not asked to interview him – which appeared to be a breach of his terms of reference.
• Notwithstanding Shatter’s concerns, the Government accepted Guerin’s recommendation that a full Commission of Investigation be set up. Guerin’s report included a draft set of Terms of Reference for such an investigation (in other words, a list of ‘what should be investigated’), including an inquiry into the roles of the Gardaí and of the Minister for Justice – i.e. of Shatter himself.
• Shatter continued to complain that he had never been interviewed by Guerin, and that therefore the findings against him were fatally flawed. He contributed to two Dáil debates where he contributed this very fact.
• In late July, Shatter launched High Court action to try and overturn some of Guerin’s findings. The government confirmed that it would indemnify Guerin (i.e. cover any legal costs or fees) in the same way as it would if Guerin was a civil servant.

The case slowly began to work its way through the High Court, with paperwork being filed on both sides. A hearing has been scheduled for April.

Here’s where we get to the events that have caused such ire this week.

• In late November, Shatter’s legal team wrote to the Ceann Comhairle, Sean Barrett, expressing concern that Guerin’s draft of the Terms of Reference would include an investigation of his own actions. He said that this would encroach on his legal action and asked for the reference to him to be removed.
• The Ceann Comhairle did not reply, on the basis that the Government had not agreed on its own version of the Terms of Reference and that it was therefore nothing to do with him.
• Two weeks later Shatter’s legal team wrote to the Taoiseach, outlining similar concerns. It is not known whether Kenny replied.
• Shortly after Shatter’s letter, the Cabinet agreed on the Terms of Reference for the investigation recommended by Guerin. The Commission of Investigation would be led by retired High Court judge, Justice Kevin O’Higgins. Its terms of reference went slightly further than Guerin’s version – including inquiry of the role of the Gardaí, Shatter, and the Department of Justice itself.
• By law, both the Dáil and Seanad are required to approve the Terms of Reference for any investigation before it can kick off. A two-day debate was slotted in for the Dáil on Wednesday and Thursday of this week, as scheduled last Friday when the following week’s agenda is laid out.
• Early this week Shatter wrote to the Ceann Comhairle, again stressing his fears that a debate on the Terms of Reference could compromise his legal action at the High Court. Barrett insists that the letter did not influence his decision – but that nonetheless, he could not allow the debate to go ahead.
• Barrett’s decision was communicated to the government at some point before Tuesday afternoon, but not to other members of the Dáíl.
• The Government’s proposed weekly schedule was changed, with the motion now to be put on Wednesday without any debate.
• On Tuesday, during the Dáil’s daily “Order of Business” discussion on its own schedule, Independent TD Mick Wallace noticed the change in the schedule and inquired as to why it was made. The Taoiseach informed him of the Ceann Comhairle’s decision. (The Ceann Comhairle was abroad and was not presiding over business himself.) Wallace asked if the decision was the outcome of an intervention by Shatter; the Taoiseach did not answer the question.
• A note explaining Barrett’s explanation was circulated to the whips of the opposition parties on Tuesday evening.
• The issue was raised again on Wednesday’s Order of Business, when the Dáil was formally asked to bypass any debate on the Terms of Reference. (The Dáil’s rules require any attempt to bypass debate, and go straight to a vote, to be approved by the Dáil as a whole in advance.) Opposition TDs again wanted to know why the planned debate was to be called off.
• In his response, the Taoiseach revealed for the first time that Shatter (and/or his lawyers) had written to both him and the Ceann Comhairle, trying to get the Terms of Reference changed, and then trying to get the debate cancelled. He repeated the Ceann Comhairle’s decision – but, again, the Ceann Comhairle was absent.
• Opposition TDs, angered that the Taoiseach had not disclosed Shatter’s intervention the previous day, appealed to him to delay the motion on the Terms of Reference until Barrett was back in Ireland and in an position to explain his rationale. The Taoiseach declined and ploughed ahead with a vote to bypass the debate.
• The opposition walked out of the Dáil, in protest at the Ceann Comhairle’s decision and the government’s refusal to delay the vote until Barrett’s decision could be accounted for.
• Alan Kelly told that night’s weekly meeting of the Labour Parliamentary Party that Barrett had opened the door to a “constitutional crisis”, by creating a precedent where anyone could stifle a Dáil debate by initiating legal action.
• This morning’s Irish Times revealed Shatter’s most recent letter to the Ceann Comhairle, in which he claimed that any debate on the Terms of Reference would be “an actual attempt by the Dáíl to encroach on the function of the courts”.
• Barrett gave an interview to RTÉ Radio, seemingly angered that the Irish Times piece suggested the Shatter letter was an influence in his decision.
• Barrett was asked about the reported reaction of Alan Kelly.  “Alan Kelly has no business saying what he said, because he didn't know the facts,” he answers.
• Barrett is asked about the potential motivations of Fianna Fáil and Sinn Féin in questioning his decision. Are they “out to undermine you, to get you?” “Of course they are,” he answers.
• Both Fianna Fáil and Sinn Féin issue prompt statements calling on Barrett to withdraw the latter claim. Sinn Féin has previously said it has no confidence in Barrett, and Fianna Fáil claims it will withdraw its confidence in him unless the remarks are withdrawn.

And there you have it. The various scandals surrounding Alan Shatter continue to run – and the Ceann Comhairle’s future is now also up in the air.