A Senate crossbencher has joined calls for the removal of the GST from breastfeeding aids, saying it "penalises newborns and mums".

The Senate agreed to a motion from Liberal Democrats senator David Leyonhjelm yesterday, urging the Government to discuss removal of the GST from breastfeeding aids, along with tampons and other sanitary products, when it next meets with state treasurers.

"Breastfeeding aids are essential healthcare products for many mothers and their babies and all medical evidence points to breastmilk being best for infants in the first six months of their lives," Senator Leyonhjelm said.

"Yet we have this inconsistent hypocritical tax system where products that encourage and facilitate breastfeeding attract a 10 per cent levy while infant formula, quite rightly, remains GST-free."

David Leyonhjelm has criticised Australia's "hypocritical" tax system. ( ABC News: Matt Roberts, file photo )

Treasurer Scott Morrison announced earlier this month that the Government would move to have the GST removed from tampons and other sanitary products, with all states indicating they would support the proposal.

Advocates and mothers told the ABC last week the GST on breastfeeding aids is another example of the "sexism" and discrimination in the GST.

The aids — including breast pumps, nipple shields and supplemental nursing systems — are not on the GST-exempt list, which includes other health items such as condoms, nicotine patches and incontinence pads.

Infant formula is GST exempt as a "basic food".

The ATO collects about $2 million a year from mothers on breastfeeding aids and equipment, according to ANU public health academic Julie Smith.

Senator Leyonhjelm said Federal Health Minister Greg Hunt has the power to declare goods like the breastfeeding aids GST-free, a power that has been used by previous ministers to exempt items including lubricants, folic acid and sunscreen.

However, LNP minister James McGrath told the Senate the Government had no plans to remove the GST from breastfeeding aids.

"A change to the rate or base of GST would need to be supported by all the states and territories," he said.

Late yesterday afternoon, the Senate also voted to censure Senator Leyonhjelm for "derogatory, defamatory and sexist" statements he made to Greens senator Sarah Hanson-Young.