South Australian Greens MP Tammy Franks will push to have tax charges thrown out of court after being given permission to withdraw her guilty pleas.

Franks had pleaded guilty to 10 charges of failing to lodge tax returns between 2001 and 2010 but has now asked that her plea be withdrawn, based on legal advice.

Her lawyer has told Adelaide Magistrates Court there would be a miscarriage of justice if the plea were not withdrawn.

He says an infringement notice served on her was misleading and defective.

The lawyer wants the case withdrawn.

The court has also been told $21,500 Franks owed had been revised down after she lodged her outstanding returns and it was possible she may now be due a refund.

The matter has been set down for pre-trial discussions in May.