Sinn Fein leader Gerry Adams last night faced a barrage of criticism after he weighed in behind former IRA chief and convicted tax cheat Thomas 'Slab' Murphy.
Mr Adams has been under pressure in recent days to address his relationship with Murphy who he previously insisted was not a criminal - but rather a "good republican".
Within hours of Murphy's conviction for tax fraud last week, Sinn Fein issued a statement saying Mr Adams would not be discussing the trial as it had not completed.
But in a shock development, Mr Adams last night issued a strong defence of Murphy who he claimed had been "treated unfairly" by the justice system and "his rights have been denied".
The Sinn Fein leader's remark led to outrage among senior politicians who said it was entirely inappropriate for Mr Adams to back a convicted tax fraudster if he was seeking to be elected to Government.
Fianna Fail leader Micheal Martin said the comments show Sinn Fein is more concerned with protecting their own than "respecting and enforcing the rule of law".
"Decent republicans are tax compliant," Mr Martin said.
"This is yet another example of Adams not facing up to the paramilitary criminality that is ongoing in parts of the North and border counties.
"His comments, when read alongside the recent independent report into paramilitary activity in the North, provide a chilling insight into how Mr Adams and his organisation do their business," he added.
Junior Finance Minister Simon Harris said there would be public outrage if any other party leader was to back a convicted criminal.
"If any other party leader not only refused to condemn the actions of an individual convicted of a crime but sought to somehow defend their actions there would be an outcry," Mr Harris told the Sunday Independent.
"When people evade tax it is the citizens of this State who actually lose out. For a man who constantly professes to being concerned about protecting the public services it seems bizarre that he thinks his buddy should not have to pay his taxes," he added.
Renua leader Lucinda Creighton also lashed Gerry Adams' support for Murphy, saying it "sends out a dangerously equivocal message".
"The essence of being a good republican is respect for the law and paying taxes that sustain critical services. Mr Murphy has failed on all those counts," she said.
Murphy denied any wrongdoing during his trial.
In his statement last night, Mr Adams said everyone has a "duty to pay the taxes for which they are liable".
"There can be no equivocation on this whatsoever. Those who for any reason have been in default of tax returns need to rectify this and need to ensure that tax returns are in order and in accordance with the law," Mr Adams said.
However, he added: "I believe that Tom Murphy has been treated unfairly. All citizens have the right to be judged by a jury of their peers.
"It is extraordinary that a case involving a failure to complete tax returns is heard before a non-jury court. Tom Murphy's rights have been denied to him. There have been many prominent public figures accused of tax irregularities including TDs. They have not been treated in the same fashion as Mr Murphy. Neither have they been labelled as criminals by those media outlets currently writing lurid headlines about Mr Murphy.
"I have been asked if I consider Tom Murphy a good republican. The answer to that is yes."