Humza Yousaf’s judgment has been called into question over his staunch support for Michael Matheson.

The First Minister has long backed the Falkirk MSP, describing him as “a man of integrity and honesty” even after he admitted lying.

The SNP leader also initially claimed that Michael Matheson’s £11,000 claim was a “legitimate parliamentary expense” and that the matter was “closed.”

READ MORE: Michael Matheson quits as health secretary

On Thursday morning, Mr Matheson quit as Health Secretary saying it was in the "best interest of myself and the Government.”

The resignation led to angry clashes during First Minister’s Questions with Presiding Officer Alison Johnstone having ro repeatedly appeal for calm.

Mr Ross asked if he regretted describing Mr Matheson as a “man of integrity and honesty.”

Mr Yousaf said his health secretary had made a mistake and apologised, seeking due process from the SPCB investigation.

He said: “I think someone who has served this Parliament, served his country, served the Government, not for years but for decades – he should be afforded that due process.”

The SNP leader said it is “galling” for the Tories to raise integrity in public life. He pointed to Mr Ross’s support for former prime minister Boris Johnson.

The Scottish Tory leader told MSPs "Michael Matheson was dishonest about his £11,000 iPad bill. He made a false claim for thousands of pounds of taxpayers’ money.

"He misled the public, the press and this Parliament. He kept on being dishonest, even as his story changed.

"He has resigned, but Humza Yousaf should have sacked him the minute it became clear that Michael Matheson had not told the truth.

"In the former health secretary’s lengthy letter, there is not one word of apology to the people of Scotland for what he did and for his dishonesty. I hope that the First Minister will apologise on his behalf."

He asked why Mr Yousaf had continued to "have this disgraced minister in his Government for months after the situation first came to light?"

The First Minister replied: "As I said, Michael Matheson reiterated in his letter that, as the process is coming to a conclusion, he has offered his resignation, and I have accepted his resignation.

"I remind Douglas Ross that, when it comes to mistakes being made, he forgot to declare tens of thousands of pounds of income—he simply forgot to do that. I do not think that I asked for Douglas Ross’s resignation at that time, because we understand that mistakes can happen.

"Douglas Ross said that Michael Matheson did not apologise, but that is incorrect."

He said in his personal statement Mr Matheson "reiterated his apology on numerous occasions for the mistake that he had made."

"He did make a mistake; I am not suggesting that he did not. All that I am suggesting is that a man who has served this Parliament for many years—decades, in fact—and who has worked diligently and hard in every role that he has been in should be afforded due process.

"He has been afforded that due process and has come to the conclusion that he should stand down."

Mr Ross said the First Minister had backed Mr Matheson "every step of the way."

"Even when the former health secretary’s story changed, Humza Yousaf was still there defending him.

"He stood by him even when Michael Matheson had to cancel appearances at general practitioner surgeries and stop doing his job to avoid scrutiny.

"Humza Yousaf let Michael Matheson continue to be health secretary while he was distracted and was a distraction.

"The First Minister was just about the only person who still supported Michael Matheson. Humza Yousaf staked his own personal reputation on backing the former health secretary.

"Why was he willing to tolerate such dishonesty?"

The First Minister said the government had been focused on the recovery of the NHS.

READ MORE: Michael Matheson to get £12k golden goodbye

Mr Yousaf said polls show the public still back the SNP to run public services.

“How dare Douglas Ross stand here and talk about standards in public life,” he said, claiming Prime Minister Rishi Sunak had “punched down” by making comments in the House of Commons about transgender people.

“I’ll certainly not be taking any lectures from the Conservatives on standards and integrity in public life,” Mr Yousaf added.

An investigation into the bill by the Scottish Parliamentary Corporate Body (SPCB) is expected to release its findings imminently, with reports on Thursday morning suggesting it was likely to be a tough outcome for Matheson.

Speaking after First Minister’s Questions, Mr Yousaf’s official spokesperson said the two men had spoken by phone on Thursday morning.

He said Mr Matheson had decided to resign after the media suggested the report was going to be difficult.

Asked if Mr Yousaf still believed that Mr Matheson was a man of honesty and integrity, he replied that did.