Jade Walford, 16, had been fitted for a £250 dress and was looking forward to joining her mates for a night to remember at Mexborough School's prom night.

But the school insists that the prom, on May 23, is a special treat for pupils who meet set attendance rates and pupils failing to meet them were all told they were not allowed to go.

Jade said: "I don't think it's right. Last year they started a similar rule, but everyone was allowed to go in the end - even people who had been excluded. It would have been better if it was decided on behaviour but people do get poorly. All my mates are going and it will probably be the last time everyone will be together."

Jade's mum Paula Walford, who is unemployed, said it had been a struggle to pay for the white and pink ballerina dress, which will now go unused.

Paula said: "I had promised Jade I would buy the dress and when I found out she couldn't go it was too late to do anything about it. Jade has been ill and we have had a lot of problems this past year. She doesn't deserve this.

"She's not a naughty kid - she has had genuine reasons for being off school and she has had that much going off in her life.

"If she had been naughty it would be fair enough. I have nothing against Mexborough School, it is a very good school. I can understand the principles behind the ban but there are genuine reasons for her being off. I understand other youngsters were allowed to go after they talked to the teacher."

Headteacher Jan Campbell would not comment on individual cases or say how many children would be missing the prom due to the ruling.

But she told the Times: "In September 2007 all year 11 pupils were told we wanted to invite them to a Prom but that it was linked to attendance. I judge attendance at this school to be inadequate. What I wanted to do was put in place some incentives, particularly for year 11s.

"Attainment and achievement are linked to attendance. The invite to the prom was automatic for satisfactory attendance and we stressed this was a privilege not a right.

We have reported attendance totals regularly since then to parents. The national average attendance for a child was 92 per cent. When I first came to this school it was 84.9 per cent for year 11 and it is now 87.6 per cent.

"An Ofsted report in November said we had inadequate attendance. I think it strengthened our resolve to do something about it. We introduced lesson monitoring and truancy calls where we text parents if we feel there is an issue. We work very closely with the educational welfare service.

"One parent has thanked us for keeping to our word and giving an incentive to her son to improve his attendance. We look at individuals if there are many separate spells of absence that need to be considered. There is a difference between a child who has had an operation or a communicative disease. There is little we can do about that. Attendance is a priority, children cannot learn if they are not there."

• What do you think about the school's policy? Is it right to punish non-attendance in this way or should all school leavers be able to enjoy the end of year prom? Write to us at Letters, South Yorkshire Times, 27-29 High Street, Mexborough; email letters@dearnetoday.co.uk; or comment on the story here on our website.