GST hike 'just like cheating on your wife'

Increasing the rate of the GST is just like cheating on your wife, apparently.

It gets easier every time you do it, Liberal Democrats senator David Leyonhjelm says.

"The records of the GST show put it up once, then it gets easier to put it up next time," he told reporters in Canberra on Thursday .

"It's like cheating on your wife - the first time it's really tough and after that it gets easier."

Nationals senator Matthew Canavan took a different tack, describing a hike in the GST as the "Thermomix of Australian policy".

"It can do everything - it can bake, it can make soup, it can improve your love life, it can do everything but it can't," he said.