Australian MP Barnaby Joyce has blamed a mixture of alcohol and prescription drugs after he was filmed lying on a Canberra street talking loudly into his mobile.
On Friday, the Daily Mail published video showing the Nationals MP and former deputy prime minister on the ground in the inner suburb of Braddon after sitting on a planter box and falling off.
"Look, obviously I made a big mistake," Mr Joyce told Seven's Sunrise programme on Monday.
"There's no excuse for it.
"There's a reason ... they say certain things happen to you if you drink (while on medication) and they were absolutely, 100 percent, right."
The prime minister has called on the coalition to answer for Mr Joyce's actions, which have cast doubt over his future on the opposition front bench.
But senate leader for the Nationals Bridget McKenzie said he would remain in his position and the party's focus was on moving forward.
"It's about getting Barnaby back to work, focusing on his welfare, making sure he can manage the medication appropriately," she told Nine's Today show.
"Those of us that are in the public eye are subject to greater scrutiny and I am concerned that somebody chose to video it instead of checking if he was okay."
Asking if he was angry someone filmed the incident rather than helping him, Mr Joyce said "that's a question for them".
"To me, the good Samaritan was the Indian taxi driver who pulled over as I was walking home and said 'do you need a lift mate?', which I obviously did," he said.