Prime Minister Scott Morrison has described as "regrettable" his own senators' decision to back a motion declaring "it is OK to be white", while the Coalition's leader in the Senate has apologised and blamed an "administrative error".

Key points: The Coalition's decision to endorse the motion sparked immediate backlash

The Coalition's decision to endorse the motion sparked immediate backlash Senator Mathias Cormann later said the Coalition had actually resolved to oppose the motion

Senator Mathias Cormann later said the Coalition had actually resolved to oppose the motion Labor voted against the motion

The motion, moved by One Nation leader Pauline Hanson on Monday, was narrowly defeated 28 votes to 31, despite the Coalition's backing.

It called on the Senate to acknowledge the "deplorable rise of anti-white racism and attacks on Western civilisation" and that "it is OK to be white" — a phrase commonly used by white supremacists.

Facing an almost immediate backlash, Attorney-General Christian Porter, whose office directed Coalition senators to vote in favour of the motion, defended the move on social media.

"The Government senators' actions in the Senate this afternoon [Tuesday] confirm that the Government deplores racism of any kind," he said.

Loading

That message was then retweeted and endorsed by Finance Minister Mathias Cormann.

Loading

But on Tuesday morning a clearly unimpressed Mr Morrison described his senators' support for the motion as "regrettable", prompting Senator Cormann to apologise a short time later.

"We should have opposed the motion when it came up in the Senate yesterday [Monday]," he said.

"As the Leader of the Government in the Senate, I take responsibility for that error and I'm sorry that it happened.

"It is indeed regrettable."

Sorry, this video has expired The Prime Minister responds to questions over Liberal Party support for Pauline Hanson's controversial motion.

Senator Cormann said the Coalition had actually resolved to oppose the One Nation motion when it was first raised in September, but blamed an "administrative error" for what transpired.

Mr Porter has also sought to clear up his role in the debacle, saying the wording of the motion was misinterpreted by his office and that he did not see it himself.

"An early email advising an approach on the motion went out from my office on this matter without my knowledge," he said in a statement.

"As Minister Cormann said this morning [Tuesday] this was the result of an administrative error, including on the part of my office."

Illustrating the level of confusion within Coalition ranks, LNP MP Luke Howarth said there was no need for the Government to apologise, arguing it had only given the story more air.

He also sought to defend his colleagues, arguing they would not have known the phrase had a more sinister meaning.

"I believe the Government should have let it die yesterday [Monday]," he told Sky News.

'Craven and pathetic attempt to clean up your mess'

Labor senator Penny Wong rejected the Government's explanation, saying the motion had been on the notice paper for weeks and there was no way its meaning could have been misinterpreted.

"This is just a craven and pathetic attempt to clean up your mess," she told the Senate.

"It's a phrase created by right-wing extremist groups in the United States to help convert people to the cause of neo-Nazis and groups like the Ku Klux Klan.

"There is nothing innocent, nothing unknown, nothing hidden about this phrase."

Following a passionate debate in the Chamber on Tuesday afternoon, Senator Cormann convinced the Senate to "recommit" the motion and this time it was defeated unanimously.

The author of the motion, Senator Hanson, mocked the Government's "remarkable" and "unforeseen backflip", claiming Mr Morrison and Senator Cormann must have woken up with "white guilt".

"This Government is either so worried about the outcome of the weekend's Wentworth by-election that they feel the need to pander to left-wing extremists that believe it's not OK to be white, or they blindly vote on important motions, bills and legislation without proper consideration," Senator Hanson said in an earlier statement.

Sorry, this video has expired Pauline Hanson says white men most demonised group in Australia.

Among those who backed the motion was Kenyan-born Liberal senator Lucy Gichuhi, who took to Twitter to clarify that she is opposed to "white supremacy" and "black supremacy" and that the Government "condemns all forms of racism".

During the debate, crossbench senator Derryn Hinch labelled the motion "obscene" while Greens leader Richard di Natale argued it was a white supremacist slogan.

Labor also voted against the motion and attacked Coalition senators for backing it.

Loading

Loading

Loading

Senate motions ultimately mean very little and are often used by members to make a political statement, but members are free to abstain from voting.

Senator Hanson, who runs on an anti-immigration and anti-Muslim platform, is well-known for pulling headline grabbing stunts, perhaps most famously when she wore a burqa into the chamber.