He said: "If Lambeth's whistle-blowing team had listened and followed the proper procedures, I could have been spared months of misery and isolation and the school could have avoided unnecessary and detrimental upheaval. Experienced and talented teachers have left, parents have lost confidence and needy children have been neglected." Mr Walker had a tumour in his abdomen removed in February 2008 before being diagnosed with cancer on March 18, undergoing four cycles of chemotherapy over a 12-week period until June 2008.