A music teacher who was told her students were so bad they left an audience of parents cringing with embarrassment has won her claim for constructive dismissal.

And the head teacher of one of England's most prestigious schools has had his evidence called into question after his school lost the case.

Westville House Preparatory School, in Ilkley, is now facing a compensation bill after losing a tribunal hearing to its former Director of Music Barbara Boothroyd.

Mrs Boothroyd, from Keighley, handed in her resignation following criticism from head teacher Charles Holloway, who allegedly told her she had let musical standards slip.

An employment tribunal had previously heard that he claimed that an audience at the Wharfedale Music Festival was left "cringing inwardly" because the performance from Westville House pupils was so bad.

In a written decision published today the tribunal bench unanimously backed Mrs Boothroyd's claim for unfair dismissal and called into question elements of evidence given by Mr Holloway.

It said: "The tribunal found that Mr Holloway lacked credibility, and that he was at times evasive in giving his evidence."

The written decision casts doubt on the head teacher's version of events of a meeting with Mrs Boothroyd where he criticised her performance and told her that senior staff and outside assessors would be asked to sit in on her lessons.

In her evidence Mrs Boothroyd had described how she was totally unprepared for the criticism which was levelled at her when she was called into the head teacher's office last November.

And she said she felt as though she was being treated like a naughty pupil when she was asked to report to him every Monday with planning sheets for the week ahead.

"I felt worthless and betrayed. In those circumstances I felt I had no alternative but to leave," she told the hearing.

The tribunal heard the school, which was ranked number 41 in the Sunday Times list of top schools for 2003, and which charges annual fees of £5,640, failed to win any prizes at last year's prestigious Wharfedale Music Festival.

But it ruled that Mrs Boothroyd had been unfairly and constructively dismissed. The damages will be decided at a later date.

After the decision Mrs Boothroyd, of Keighley, who is not working at the moment, said: "Obviously I am very happy with the way it has gone. I am just glad it is all over now."

In a statement Westville House School said: "We are, naturally, surprised and disappointed by the outcome of the tribunal, especially as the school had no intention of dismissing Mrs Boothroyd and we consider that our actions in this matter were both fair and reasonable."