The Deputy Prime Minister has accused the former government of risking lives in its election day decision to publicise the interception of a suspected asylum seeker boat.

The ABC today revealed one of Scott Morrison's final acts as prime minister was to instruct the Australian Border Force (ABF) to issue a rare statement about the boat from Sri Lanka.

Soon after, Mr Morrison discussed the matter at an election day press conference.

The Liberal Party also sent a mass robo-text message to voters in marginal seats, urging them to back the government and its tough border policies.

Speaking after the ABC revelations, Deputy Prime Minister Richard Marles said the former government's actions on Saturday undermined border security.

"It's serious in the sense that it did make our borders less secure.

"It's serious in that it risked lives, it risked lives, and it undermined the national consensus that does exist around border security."

Sources have confirmed to the ABC that the Prime Minister's Office made a direct request to publicise the details of the sensitive ABF operation before it had been completed.

Speaking after the report emerged, Prime Minister Anthony Albanese said he believed the only reason the former government wanted the press release issued was so it could send its campaign text message.

"The prime minister's office contacted my office in the middle of Saturday and we indicated it would be entirely inappropriate for this event to be politicised," he told the ABC's AM program.

"It is a clear breach of the caretaker conventions."

But constitutional law professor Anne Twomey said there didn't appear to be a breach of the caretaker conventions.

"The reason it doesn't breach the conventions themselves is that it's not making some kind of a commitment that binds the opposition in the future," she said.

"But it does potentially breach those associated issues about not politicising the public service."

The ABC has approached former prime minister Scott Morrison, specifically to ask why his office requested the Australian Border Force to reveal the boat interception, but he has declined to comment.

The unusual disclosure of operational "on water matters" is now subject to an inquiry by Home Affairs Department Secretary Mike Pezzullo, ordered this week by the new Labor government.

Professor Twomey said while there would be no consequences for Mr Morrison, there could be for the public servants involved.

"For the officials involved, there may be questions as to whether or not disciplinary action needs to be taken," she said.

"If it's found that any officials breached, for example, Australian Public Service values, which require them to act in a manner that's impartial and apolitical, particularly during an election campaign."

On Tuesday, Rear Admiral Justin Jones confirmed the boatload of asylum seekers intercepted near Christmas Island on election day had now been returned to Sri Lanka after appropriate assessments.