They thought they had seen the last of grotty prefabs when their top performing school celebrated the opening of a new £2 million classroom block three years ago, as part of countywide improvements.

They thought they had seen the last of grotty prefabs when their top performing school celebrated the opening of a new £2 million classroom block three years ago, as part of countywide improvements.

But the joy when Wymondham High School said goodbye to 14 out of its 19 ageing mobile classrooms in February 2005 - the

highest number for any Norfolk school at that time - turned out to be short-lived.

For some of the old buildings have been brought out of mothballs and are back on site again in a bid to accommodate a rapid increase in pupil numbers because of recent housing developments within the area.

There are now a total of 10 mobiles with another two on the way, subject to the necessary planning consent - sparking fierce criticism from the school's headteacher, Victoria Musgrave, who joined the staff in September and sees it as a retrograde step.

Wymondham High is one of the top schools in the country with an impressive record of academic success and achievements, and she believes her students deserve a better deal.

“We feel extremely disappointed to have children learning in mobile classrooms and feel it is the responsibility of the local authority to look at the provision of secondary education in Wymondham and invest in our oversubscribed school buildings, and not simply expect us to teach more and more children in already overcrowded accommodation,” she said.

“We have got 1,520 students, the sixth from has grown to 300, and year seven is horrifically over-subscribed. We have almost 100 per cent room usage and over 140 science lessons not taught in practical science labs.

“Ironically, some of the mobiles they brought back last summer are the same ones they took away in 2005, and they are as grotty as ever, and they expected us to find the tables, chairs and kit to go in them. I am very angry about it. In winter they are freezing, in the summer they are hot, and children have to walk across virtual ploughed fields to reach them.”

The population boom looks set to continue, with developer Pelham Holdings seeking consent for 3,000 new homes in the town alone. But Mrs Musgrave said: “I have no issue with the school growing providing the local authority will provide proper accommodation for our students.”

County council spokesman Kate Gooding said two mobiles were installed this term to cope with the school's growing population, particularly in year seven and the sixth form.

“We are working very closely with the school and the Greater Norwich development Partnership (GNDP) to plan places for secondary schools in the Wymondham area in the future and these mobiles are expected to be a temporary measure. A strategy is being developed for secondary school development in the greater Norwich area, taking into account population growth and the government's Building Schools for the Future programme. We would always seek to gain funding for school places as part of any development,” she explained.

“We had managed to reduce the number of mobile classrooms in Norfolk from nearly 600 in December 2007 to just over 400 in December 2007. However, we have always said that we need to keep some mobiles to cope with rapid or temporary expansion. We have had to put mobiles in at a small number of schools for this reason,” she added.