Barnaby Joyce has cited a combination of alcohol with a prescription drug in leading to the February 7 video of him swearing into his phone while lying on a Canberra street.
The former deputy prime minister told morning television he had "made a big mistake".
"There's no excuse for it, there's a reason," he told Sunrise on February 12.
"It was a very eventful walk home, wasn't it?
"I'm on a prescription drug and they say certain things may happen to you if you drink and they were absolutely 100 per cent right."
On the weekend a chalk outline and plaque were added to the scene on Braddon's Lonsdale St, where the Nationals frontbencher was filmed lying on the footpath while talking on the phone.
The plaque commemorates Mr Joyce "being totally f--- a--- drunk that time. 8th Jan 2024".
Mr Joyce said in a statement he was swearing at himself for having fallen over, after the Daily Mail reported he was heard mumbling "dead f---ing c--t" into the phone.
Mr Joyce said he had been sitting on the planter box on the way back to his accommodation when he fell off.
Prime Minister Anthony Albanese told reporters in Ballarat an explanation was required and a "response of the Liberal and National Party leaders".
"I think people will also think to themselves, what would the response be if that was a minister in my government being seen to be behaving in that way?"
Opposition Leader Peter Dutton said he would "have a chat" with Mr Joyce in the coming week.
"It's pretty rough when people are walking past somebody who might need support," he told Sky News of the video.
"I understand a chalk mark has been drawn on the footpath. It could only happen in Canberra where all those Greens and Labor staffers are."
