The PSNI's rank and file have passed a motion of no-confidence in the senior officer who replaced former PSNI Chief Constable Simon Byrne.
Deputy Chief Constable Mark Hamilton assumed the responsibilities of his former boss after Mr Byrne stepped down on Monday.
But the Police Federation has now said it does not support Mr Hamilton either.
He was also involved in the decision to discipline two probationary constables for a controversial arrest after a Troubles commemoration in 2021.
They appealed the decision and a critical court judgement found the move had been motivated by a perceived or real threat that Sinn Féin would withdraw support for policing if the matter was not addressed promptly.
It piled pressure on Simon Byrne and together with the fallout from a huge data breach which affected all his officers and staff, was the catalyst for him to quit.
Federation chair Liam Kelly, whose organisation represents around 6,500 officers, said the decision to vote no-confidence in Mr Hamilton had been taken at an extraordinary meeting of its executive.
He said: "Our Federation is of the collective view that because of his involvement in the decisions concerning the Ormeau Rd incident, and the real or perceived political interference in that process, we can have no confidence in him."
Mr Kelly said they also wanted clarity on whether the PSNI still planned to appeal the critical court judgement as Mr Byrne suggested just days before he left office.
The threat of a no-confidence motion by the federation in Mr Byrne was a big motivating factor in his decision to leave.
The UUP had also called for Mr Hamilton to step aside.
Policing Board member Mike Nesbitt said he understood the federation's decision had been unanimous.
"We have consistently identified the fact that the problems with the PSNI go well beyond one man and that removing Simon Byrne as Chief Constable does not cure all ills," he said.
In a statement, the Policing Board said it "will not be making any comment regarding the vote by the Police Federation until members have had the opportunity to discuss".
