Senior Coalition leaders have urged Barnaby Joyce to take personal leave after video emerged of the Nationals MP lying on a Canberra footpath talking loudly into his mobile phone.

Joyce has blamed the “embarrassing” incident on mixing prescription medication with alcohol.

Video published last week by the Daily Mail shows the 56-year-old opposition frontbencher lying on the ground in the inner suburb of Braddon, after he had apparently tumbled off a planter box.

The video, which has since gone viral, has led to questions about the former deputy prime minister’s fitness to remain on the opposition front bench.

Joyce was late to arrive at Parliament on Monday. He got there almost an hour after question time began and ahead of a Nationals party room meeting.

Nationals leader David Littleproud said he had urged Joyce to take personal leave.

“His behaviour was not acceptable but there were circumstances that drove that and that my job is to create the environment for him to be able to address that,” he told Seven’s Sunrise.

“I’ve strongly encouraged him to take that leave to be able to address it.”

Littleproud confirmed that Opposition Leader Peter Dutton had also spoken to Joyce about the incident.

“This is something that he’s deeply embarrassed about,” he told Sky News on Monday.

“He’s made that very clear that this isn’t normal behaviour that he undertakes and there are extenuating circumstances surrounding that and obviously, we will support him in making sure that, anything that he does need, he gets.”

Littleproud flagged more talks with Joyce. He said the New England MP was dealing with some “distressing” personal issues, and would be welcomed back once they were resolved.

“There are some other personal circumstances around his family, and some unfortunate circumstances that have prevailed with other family members – that are distressing to Barnaby … and he needs to address those,” he said.

Joyce has admitted to a mistake.

“There’s no excuse for it,” he told Sunrise on Monday.

“There’s a reason … they say certain things happen to you if you drink [while on medication] and they were absolutely, 100 per cent, right.”

The government has called on the Coalition to answer for Joyce’s actions, with Finance Minister Katy Gallagher saying the situation was “incredibly sad”.

“These things do nothing for the profession of politicians … it confirms, in people’s minds, the public’s minds, negative association with politics, and I think that’s a real shame,” she told ABC radio on Monday.

“But personally, I hope he gets the help he needs because it’s a very unusual position for someone of that age to be in.”

Labor MP Tania Lawrence said the behaviour of the Nationals MP was embarrassing.

“We are examples to our community young and old, we represent Australia to the international dignitaries and visitors we meet each week,” she told parliament.

“We are under the spotlight, and we should act accordingly, and if we can’t, then we must also be able to understand that there isn’t a single member here who is irreplaceable.”

-with AAP