The only way is ethics
Mick Wallace has insisted that he is fit to be a TD despite making a false Vat declaration and under-declaring his company's tax liability by €1.4m. (€2.1m under the terms of his settlement with Revenue, including interest and penalties.) This tax liability will never be paid given his company is insolvent. However, Mick Wallace himself is tax compliant, hence his insistence on keeping his seat.