The Greens have revived the tampon tax debate, calling for the scrapping of the "sexist, discriminatory" tax on women's bodies.
The upper house is debating laws allowing GST to be collected on imported goods worth less than $1000, raising $300 million over three years.
Greens senator Larissa Waters says that revenue will more than cover the shortfall if the GST is removed from pads and tampons, insisting independent costings from the Parliamentary Budget Office show the states and territories would still be $185 million ahead.
She's collected more than 11,000 signatures within days calling for the removal of the tampon tax.
Senator Waters insists there is no longer a revenue excuse for the "sexist, discriminatory" tax on necessary items, especially given condoms are GST-free.
"When the GST laws were drafted, perhaps there were no women in the room," she told parliament on Monday.
"Guys, it's biology, it's not a luxury."