The Court of Appeal has quashed the decision of the Garda Commissioner to dismiss a Waterford-based garda sergeant from the force after she was convicted of assault five year ago.

The three judge appeal court ruled the commissioner had not acted lawfully within the regulations in dismissing Martha McEnery without giving separate consideration to the facts surrounding her breach of discipline.

The issue of her dismissal may now be reconsidered.

McEnery was found guilty of assaulting Anthony Holness in January 2010.

She was given a suspended sentence of four months in prison.

McEnery appealed, but her conviction was upheld by the Court of Criminal Appeal.

She later took a High Court challenge to the Garda Commissioner's decision to dismiss her from the force as a result.

She lost her case in the High Court but this afternoon a three judge Court of Appeal allowed her appeal and quashed the decision to dismiss her.

In her High Court proceedings, her lawyers argued that the simple fact of a criminal conviction in the absence of other reasons could not constitute grounds for summary dismissal and the fact of such a conviction did not absolve the Garda Commissioner from conducting his own inquiry into her conduct.

She argued that the commissioner did not give her adequate reasons for his decision.

Lawyers for the Garda Commissioner argued that there could be no doubt as to the facts constituting the breach of discipline involved.

They also argued that she was fully aware of the indisputable facts upon which the decision to dismiss her was based and the reason for it.

The High Court dismissed Ms McEnery's challenge to her dismissal.

 Delivering the decision of the Court of Appeal, Mr Justice Peter Kelly said the power of summary dismissal provided for in Regulation 39 of the gardaí disciplinary regulations was an exceptional one which may only be used in very limited circumstances.

He said the regulations contained comprehensive procedures for dealing with garda indiscipline and provided for the establishment of a board of inquiry and an appeal board.

Therefore summary dismissal was an exceptional power and the courts had to ensure that power was exercised properly and within the law.

He said the principal point made on the appeal was that the commissioner had conflated two separate matters - the material facts and the relevant breach of discipline.

The court agreed with McEnery that the certificate of conviction could not of itself amount to all the material facts and gave no information as to nature of the assault, the manner in which is occurred or the circumstances which gave rise to the jury acquitting her on one charge and convicting on a lesser assault charge.

The judge said the commissioner was obliged to consider "not just the conviction which constitutes the breach of discipline but also the material facts which may be extraneous to the actual breach but nevertheless material".

He said the commissioner decided to proceed with dismissal and in doing so concluded that the holding of an inquiry under the regulations could not affect his decision in the matter.

Mr Justice Kelly said the commissioner did not proceed in a lawful manner and by treating the material facts and the breach of discipline as one and the same he "blinkered himself" from a consideration of the material facts, depriving the appellant of her right to have the material facts which gave rise to the breach of discipline fully considered.

He allowed the appeal and said the commissioner was not correct in law and the decision to dismiss ought to be quashed.

He said such an order did not preclude the respondent from taking whatever lawful steps deemed appropriate concerning McEnery pursuant to the regulations.