France calls leaked Macron text 'new low' in Australia subs row

The Australia-France row over the collapse of a submarine deal reached an "unprecedented new low" when a text message from the French president to Australia's leader was leaked, France's ambassador to Canberra said Wednesday.

Emmanuel Macron sent the message to Prime Minister Scott Morrison two days before Australia announced that it had torn up a decade-old multi-billion-dollar contract with France to build a new fleet of submarines.

Paris reacted furiously, and Macron added to the furore at the weekend by accusing Morrison of lying to him, a charge the Australian has batted away.

In a fiery speech on Wednesday, French ambassador to Australia Jean-Pierre Thebault said the leaking of the private text was an "unprecedented new low".

"You don't behave like this on personal exchanges of leaders who are allies. But maybe it is just confirmation that we were never seen as an ally," he told Australia's National Press Club.

"Doing so also sends a very worrying signal for all heads of state: beware, in Australia, there will be leaks. 

"And what you say in confidence to your partners will be eventually used and weaponised against you one day."

In the message, Macron had asked Morrison: "Should I expect good or bad news for our joint submarine ambitions?"

Reports said the leak could have been engineered by Morrison's office in retaliation for the "lying" charge.