Barnaby Joyce has blamed a mix of prescription drugs and alcohol for his “embarrassing” footpath incident.

On Monday morning the Nationals MP told Sunrise he had made a “big mistake” but there was a “reason” he was lying on the ground just before midnight on Wednesday.

“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. They did,” he said on Channel Seven.

“So you mixed alcohol with prescription medication, did you, and this is what happened?” asked host Nat Barr.

Joyce replied: “That’s exactly what I said, yep.”

Nine newspapers had been reporting there was a medical explanation for why Joyce was seen lying on the Canberra pavement.

Sources earlier said Joyce was feeling the effects of his medication mixing with alcohol when he fell off the planter box while talking to wife Vikki Campion on the phone.

The nature of the medical issue or medication has not been revealed.

Earlier, Prime Minister Anthony Albanese said it was up to Joyce to “explain the circumstances” around his episode as the issue continued to grab headlines.

Albanese had initially not weighed into the commentary surrounding the “embarrassing” video of Joyce on the ground, but on Sunday responded to questions.

“It is up to Barnaby Joyce to explain the circumstances around this,” he said.

“People will certainly make their own judgments on that.

“People will see that footage, they will look for an explanation that has some credibility and they’ll look for leadership from the leader of the Liberal Party and the leader of the Nationals Party about this.”

Nationals MPs are expected to discuss the episode, which occurred in Canberra last week, at a scheduled meeting on Monday.

Opposition Leader Peter Dutton said he would talk to the Nationals front-bencher and former deputy PM this week.

“It’s pretty rough when people are walking past somebody who might be in need of support,” he said.

“I understand a chalk mark has been drawn on the footpath – it can only happen in Canberra where all those Greens and Labor staffers are.”

Barnaby Joyce has appeared in chalk on the sidewalk. Photo: Reddit

Nationals leader David Littleproud said it was “not normal behaviour”.

On Monday morning, Greens leader Adam Bandt called out double standards on behaviour.

“I would ask that if people say that there are health issues that have led them to a certain point, that we apply that fairly, and that we look at people who have been kicked off JobSeeker because they’ve missed an appointment because they’ve got a health issue, or people who have lost their job because they’ve got a health issue,” he said.

Last week, Joyce confessed his “embarrassment” after the bizarre footage, obtained by the Daily Mail, emerged on Friday.

It showed the veteran Nationals MP lying on Lonsdale Street, in the Canberra suburb of Braddon, shortly after 11.30pm on Wednesday.

Sources told the publication that 56-year-old Joyce was sitting on a large pot plant while having an animated telephone conversation when he fell off and “rolled around”.

He continued his call while lying on the ground, dressed in a suit and what appeared to be the same tie he wore in Parliament earlier on Wednesday.

Much of his conversation is muffled in the footage but some profanities – including what is apparently “dead f—ing c–t” – are clear.

Joyce told the publication on Friday the scene was “very embarrassing”.

“I was walking back to my accommodation after Parliament rose at 10pm,” he said.

“While on the phone I sat on the edge of a plant box, fell over, kept talking on the phone, and very animatedly was referring to myself for having fallen over.

“I got up and walked home.”

In a separate statement, Campion told News Ltd that he was talking to her at the time. She said the expletives weren’t aimed at her.

“No, I think he was calling himself one, he likes to self-flagellate,” Campion said.

She said she was disappointed a passerby had filmed Joyce, rather than offering help.

Campion and Joyce had a bush bash-style wedding at his family’s property in Woolbrook, in the NSW Northern Tablelands, last November. They have two young sons.

The couple’s relationship sparked the Turnbull government’s infamous 2018 “bonk ban”, when it emerged the then-married and then-deputy PM was having an affair with Campion. She was a Liberal staffer at the time.

Joyce also has four adult daughters with ex-wife Natalie Abberfield.

-with AAP