The Tories have demanded an independent investigation be carried out over Justice Secretary Michael Matheson preventing Scotland's top police officer from returning to work while misconduct allegations are being probed.
Tory MSP Margaret Mitchell claimed that intervention was "without doubt the most serious example of the SNP Government's abuse of power".
Mr Matheson had raised questions with watchdogs at the Scottish Police Authority (SPA) after they informed him a decision had been made to end Chief Constable Phil Gormley's leave of absence.
Following the Justice Secretary's intervention, the decision was reversed - with Mr Gormley informed of this as he was travelling back to Scotland.
Mr Matheson insisted to MSPs that what he had done had been "entirely legitimate".
But raising the issue at Holyrood Ms Mitchell said: "It is crucial to understand that the police force is no ordinary public service, it protects the rule of law in our democracy and its serving officers have the power to lawfully deprive citizens of their most fundamental freedom, the right to liberty.
"It is therefore essential that the independence of the Force's chief constable is protected from political interference.
"Our democratic freedoms are fragile and should never be taken for granted. They rely on openness and transparency.
"The actions of the Justice Secretary must now be the subject of a full and independent investigation for example by the independent advisers on the ministerial code."
Opposition MSPs were enraged when it emerged no minutes had been taken when Mr Matheson met former SPA chair Andrew Flanagan to discuss Mr Gormely's period of absence.
He has been on special leave since September, with the independent Police Investigations and Review Commissioner (Pirc) looking into allegations of gross misconduct against Police Scotland's chief.
Mr Matheson restated the "lack of an effective process" around the SPA's decision to allow Mr Gormley's return meant he "could not have confidence" in it.
He said: "I continue to believe that my actions were entirely legitimate in terms of the accountability public bodies have to ministers for the exercise of their functions."
The Justice Secretary said the decision not to take minutes at his meeting with Mr Flanagan "was a matter for official judgement"
Labour's Daniel Johnson said Mr Matheson had "missed opportunities and ignored warnings time and time again".
He said: "Mr Matheson has been in position since 2014. For four of the five years of Police Scotland's existence he has been the minister responsible.
"Responsible for developing the governance structures the processes and procedures that surround it, responsible for the appointments to the SPA and overseeing its work. Its failings are his failings.
"Mr Matheson has had almost four years to ensure that the SPA and its board were up to the job. But after this intervention the question has to be is he up to his?"
Green MSP John Finnie, a former police officer, said the debate had turned into a "wee bit of a soap opera".
But he said: "On the issue of transparency, I'm sure the government will reflect that things perhaps could have been done better."
Liberal Democrat Leader Willie Rennie said Mr Matheson had been right to ask questions of Mr Flanagan but had tried to conflate the substance of his intervention with the process around it.
Mr Rennie said the Justice Secretary "still would have kept it secret" if the intervention had not been reported in the press.