The Turnbull government has been plunged into crisis after Barnaby Joyce blasted Malcolm Turnbull for making a moral judgement on his extra-marital affair, labelling the Prime Minister’s comments “inept” and accusing him of “causing further harm” to his family and pregnant partner.

With the Prime Minister in Tasmania and unaware of Mr Joyce’s plans, the Deputy PM called an impromptu press conference at Parliament to respond directly to Mr Turnbull’s suggestion the Nationals leader had “appalled all of us”.

“Comments by the Prime Minister yesterday at his press conference… I have to say that, in many instances…they caused further harm,” a visibly angry Mr Joyce said.

“I believe they were in many instances inept and most definitely in many instances unnecessary. The reason I say that is it was public knowledge what was being repeated, it ran on the front pages of papers and all it does is reinvest in hurt of other people.

“I have to say that because I listened to it and I thought that was completely unnecessary and all that is going to do is basically pull the scab off to everybody to have a look at.”

On Thursday, Mr Turnbull held an impromptu press conference during which he personally criticised Mr Joyce for the “terrible hurt and humiliation” he caused his wife, daughters and new partner, Vikki Campion.

He said Mr Joyce should “consider his position” and revealed he had encouraged him to take leave rather than serve as Acting PM next week.

As a result of the affair, Mr Turnbull announced he was changing ministerial standards to ban ministers from having sexual relations with their staff, making it a sackable offence.

In an extraordinary press conference, an emboldened Mr Joyce dug in further amid calls for him to resign, saying he had the full support of his party room.

Asked during his Friday doorstop why he hadn’t yet resigned, he responded: “Quite simply because that is not a decision of my colleagues and the right of the leader of the National Party is to reflect on where the colleagues are and my colleagues support me.”

Asked how he could now serve alongside with Mr Turnbull, Mr Joyce said he planned to work on the relationship to get back on an “even keel”.

But he also criticised the new ministerial code of conduct announced by Mr Turnbull, saying it would create “immense fodder” for the media.

“It is the Prime Minister’s code, we will support it, and we will do our best endeavours to see it through,” Mr Joyce said.

“It goes without saying that this will create immense fodder for the good people in the media and it will obviously reverberate across all political parties.”

After Mr Joyce’s press conference on Friday, Mr Turnbull stood by his comments, though he said he was not trying to “influence the deliberations of the National Party”.

“Neither I nor my colleagues have made any criticism of the National Party by expressing views of disapproval or criticism of Barnaby’s own conduct.”

Ahead of Mr Joyce’s Friday comments, Mr Turnbull told media in Tasmania he had not called on Mr Joyce to resign because “he has to form his view on his circumstances”.

When asked whether he first learned of Mr Joyce’s affair during the New England byelection, Mr Turnbull fumbled his response, claiming he was never explicitly told of the affair.

“When you are talking about somebody in a sexual relationship of this kind … the only way you can be certain that the relationship is of that character is if one or other of the parties to the relationship actually tell you,” he said.

“There are a lot of rumours around Parliament House at any given time. I hope most of them are wrong. But no doubt, many of them are.

“I’m not going to go into the private discussions between me and Barnaby Joyce other than what I have said. But he did not come into my office and say, I am having an affair with this woman.”

– with AAP