Scott Morrison says two ministers who were the subject of a Four Corners program about a misogynistic culture in Canberra did not breach his code of conduct.
Alan Tudge, who is now acting immigration minister, has publicly apologised for the hurt his 2017 affair caused his family and former staffer Rachelle Miller.
Attorney-General Christian Porter has denied accusations of any wrongdoing, having been told by former prime minister Malcolm Turnbull reports of him drinking and being seen "in the company of young women" at a Canberra bar in late 2017 exposed him to the risk of compromise.
Mr Turnbull instituted a so-called "bonk ban" - extending the ministerial code of conduct - when media reports exposed former deputy prime minister Barnaby Joyce as having an affair with a staffer who was pregnant.
Mr Morrison, who as prime minister kept the ban in place, did not believe the ministers had breached any aspect of the code under his watch.
He said all ministers were in no doubt about his expectations in terms of behaviour.
"I think Australians understand human frailty, and I think they understand the people who work in this place are just as human as anyone else and subject to the same vulnerabilities and frailties as anyone," he told reporters in Canberra.
"(But Australians) want standards. That is why the standards are there, that is why the standards were introduced."
Labor leader Anthony Albanese asked the prime minister in parliament whether his ministerial standards "have been and will be enforced".
"It is always the case," Mr Morrison said.
"I would hope that the same standards that are set out in this document would be adopted by the leader of the opposition in relation to his own front bench."
Mr Turnbull met with Mr Porter just before making him attorney-general, telling him the reported behaviour was "unacceptable conduct for a cabinet minister".
Mr Porter told 6PR radio on Tuesday the incident raised with him by Mr Turnbull involved nothing more than having a drink with a woman in a bar.
"I have never breached that ministerial code of conduct and there's never been any suggestion I have," he said.
ABC's Four Corners program on Monday night also aired background on Mr Porter related to his attitude towards women when he was at university.
In a statement, Mr Porter apologised for some material he wrote in a law school magazine 24 years ago, but denied other reflections on his character and said he was considering legal action.
Mr Turnbull told ABC's Q&A program after Four Corners aired: "If I'd known at the time what was broadcast ... I would have made further inquiries before I made him attorney-general."
Mr Porter questioned Mr Turnbull's motivation in talking to the ABC, saying the former prime minister was never a "great fan of mine".
Ms Miller told Four Corners that her consensual affair with Mr Tudge cost her "a lot of self-confidence" and she felt powerless in the situation.
Mr Albanese told the Labor caucus they were deeply disturbing allegations and all staff deserved to feel safe and supported.
Mr Joyce argued a politician's private life should only become public when there were issues around age, agency or consent.
"If it's a consensual relationship between two adults, then if you've got a problem with that, that's a role for the police or a priest, but not another politician to be the arbiter of how two people feel about each other," he said.
Australian Associated Press