The candidate made the comments in an essay for Quadrant.
A One Nation candidate for the West Australian seat of Pilbara is in strife after articles he wrote for Quadrant surfaced in the media.
In a March 2015 article, candidate David Archibald suggests a range of welfare programs which should be cut because they support ‘lifestyle choices’.
“The first that springs to mind is single motherhood,” he writes.
“These are women too lazy to attract and hold a mate, undoing the work of possibly three million years of evolutionary pressure.”
“This will result in a rapid rise in the portion of the population that is lazy and ugly. We know what causes pregnancy these days, so everyone who gets pregnant outside of marriage is a volunteer.”
Mr Archibald confirmed with the ABC that he stands by the comments.
Federal Labor frontbencher Anthony Albanese, himself raised by a single mother, has called for One Nation to drop the candidate ahead of the March 11 state election.
"The idea that if you have a single mother you are somehow less of a human being, really belongs way back in the dark ages," Mr Albanese said.
The resurgent minor political party has struggled with a string of controversial candidates which have raised questions about the party's vetting process.
But for now it appears the party is standing by David Archibald.
WA One Nation leader Colin Tincknell has said “it’s not the end of David.”
In comments to The Australian last night, he characterized the comments as “tongue in cheek” and said Mr Archibald had been “a bit naughty”.
In the article Mr Archibald also takes aim at childcare funding, spending on Indigenous affairs and the disability pension.
“Second, the 800,000 Australians on the disability pension. OK, not all of them. But a good proportion are able to drive cars, bash police and each other, go fishing and so on,” he writes.
In another article, Mr Archibald branded the Stolen Generations a “concocted” myth.
Earlier this week Pauline Hanson said she won't let rogue candidates destroy the ambitions she has for One Nation.
"No one, no one is going to take it over and destroy what I want to achieve, what I want to do," she said.
"I can assure you, 20 years' experience, knowledge, wisdom, understanding... I've taken over the leadership of this party."