The emergency meeting – the second in a month – was called in light of the High Court ruling that two probationary officers were unlawfully disciplined for their actions in policing a Troubles commemoration on the Ormeau Road.
Policing Board member Trevor Clarke, who has called for Mr Byrne to resign, has said that even if he doesn’t fall on his sword a motion of no confidence in him could be put forward by the board.
Mr Clarke said the Chief Constable had lost the support of politicians, his police officers and members of the public.
He said: "He’s lost the support of all the unionists [on the Policing Board], I presume there will be some independents members will have that same view.
"He cannot bring it back from this position.
“He’s leading an organisation that has difficulties but he’s now leading a workforce that has no confidence in him.”
Within the detail of the Judical Review is a note from DCC Mark Hamilton, written in the aftermath of the incident, saying that some in the republican community were saying that it would be “their Drumcree”.
The same note from DCC Hamilton, taken from the Judicial Review, states: “The [Chief Constable] received information from Sinn Fein that unless officers were suspended, they would remove support for policing.”
This has been denied by the party’s North Belfast MLA Gerry Kelly who said: “At no stage during any calls to, or meetings with, senior PSNI officers did I suggest or insinuate that Sinn Fein would withdraw support for the rule of law or policing, or remove our members from the Policing Board.”
Mr Justice Scoffield had adjudged that the suspension of one probationary constable and the re-positioning of his colleague was “because of the threat (whether real or perceived) that, if it did not do so, republican support for policing would be withdrawn”.
Mr Clarke said: “It is a matter of record that a court has found the Chief Constable’s decision-making process to have been influenced by how he believed it would impact Sinn Fein’s support for policing.
“It is notable that Sinn Fein’s initial reaction to this ruling was that it was ‘a matter for the PSNI’.
"Perhaps it is only as pressure has further mounted that further comment was issued by Gerry Kelly.
"That however doesn’t resolve the questions facing both the Chief Constable and Sinn Fein.”
He continued: “We will never know exactly what was said during the calls or meetings between Sinn Fein representatives and senior PSNI officers on that day.
"The overarching issue is why the Chief Constable felt Sinn Fein’s support for policing was so tenuous that he needed to sacrifice the careers of two officers.
“We know that a hands-off approach was taken towards the Bobby Storey funeral.
"It is clear that the differential approach towards republicans didn’t emerge on the day of the Ormeau Road incident, but predated it.
"Concerns about two-tier policing have existed over many years now but it is staggering that this has come forward so clearly in a court.
“Sinn Fein’s belated intervention on the issue doesn’t answer the questions which have been raised.”
Another man calling for Mr Byrne to go is TUV leader Jim Allister.
He was dubious about Mr Kelly’s comments that he did “at no stage … suggest or insinuate that Sinn Fein would withdraw support for the rule of law or policing, or remove our members from the Policing Board” but nonetheless said it put an onus on the Chief Constable.
Mr Allister said: “Now that Sinn Fein are claiming that they never said or insinuated that they would withdraw from the Policing Board, there is an onus on the Chief Constable and the PSNI to publish their records of contacts and messages relating to the issue because DCC Hamilton’s note recorded in paragraph 83(e) of yesterday’s judgement is very clear.”
Mr Allister commented: “If Sinn Fein hoodwinked the Chief Constable with a bluff, then he has only exposed himself to be a greater fool than previously imagined.
"That said, who can believe any Sinn Fein denial?”