A 43-year-old woman has begun a Supreme Court appeal against a High Court decision that the Minister for Education and the State have no liability for indecent assaults on her by a primary school principal.

Louise O'Keeffe, a mother of two from Dunmanway in Co Cork, was left with a €500,000 legal bill after her failed High Court action.

She is taking this appeal on the grounds that High Court judge Eamon DeValera was wrong to have found the State not liable and to have awarded costs against her. 

She also claims the trial was unsatisfactory particularly because of a delay of almost two years before the judgment was given.

Ms O'Keeffe was a pupil at Dunderrow National School in Kinsale, Co Cork.

In 1973, her mother encouraged her to take music lessons from the school principal, Leo Hickey. She had 20 lessons on the melodica in 1973. The abuse began on the second lesson.

In January 1974, Mr Hickey resigned from the school after complaints from other mothers. He went on to teach in a boys' school. In 1998 he pleaded guilty to 21 sample charges of indecent assault and was jailed for three years.

In 2006, the High Court rejected Ms O'Keeffe's claim that the State was liable for the abuse carried out by a State-recognised teacher in a State-recognised national school.

She argues Mr Justice deValera was wrong - and that he was wrong not to exercise any discretion and to award costs against her. She also claims the trial was unsatisfactory particularly because of a delay of almost two years before the judge delivered his judgment.

The State will claim Ms O'Keeffe has failed to acknowledge the essential and active role of the patron of the school - the Bishop of Cork and Ross.

The State will say that the hierarchy would not have allowed any interference in the choosing of principals or teachers - except to ensure the person chosen by the patron or the manager was appropriately qualified.

Trying to make the State liable would fail to acknowledge the limits of the Department's influence in the school but also the reality of times and, the State claims, it would have significant implications for present day national schools.

It says that if the Minister was to be held vicariously liable for the actions of individual teachers without being given appropriate control over those teachers, it would be illogical and unworkable and would involve rewriting the 1998 Education Act.

The State will also argue that any extension of liability to the Minister for assaults such as those committed by Leo Hickey would lead to the Minister being held liable not merely for events in the past, but also for a whole host of occurrences that happen every day in the 3,000 national schools around the country.

The outcome of this appeal will affect at least 200 other such cases.

It is expected to take another two days.