The Australian government has run out of diplomacy on Singapore's plan to execute convicted Australian drug smuggler Tuong Van Nguyen, 25.
The execution is only hours away and international calls for clemency have fallen on deaf ears.
By Singapore law, the death sentence was mandatory and Australia has been careful to say it must respect the laws of other countries.
Attorney-General Philip Ruddock stepped outside the careful language of diplomacy today, calling the execution "barbaric."
"It was a mandatory death sentence. We feel most remorseful this is going to happen," Mr Ruddock told Australian television.
"It's a most unfortunate, barbaric act that is occurring."
Reuters reports that Singapore and Canberra have a special relationship and Prime Minister John Howard has rejected calls for trade and military boycotts over the execution but has tried to use personal leverage in an attempt to gain clemency.
Some 420 people have been hanged in Singapore since 1991, mostly for drug trafficking, Reuters said, citing an Amnesty International report. That gives the country of 4.4 million people the highest execution rate in the world relative to population.
The Australian population is about evenly divided on whether the execution should go forward, according to polls.
The death penalty is not an option in Australia.