All schools and nurseries will have to be closed if an avian flu pandemic takes hold in Britain, Sir Liam Donaldson, chief medical officer, has advised. In a letter, leaked to the Sunday Times, he said that if the H5N1 virus were to mutate into a form easily spreadable by humans, 100,000 children of school age could die. Sir Liam said schools, nurseries and childcare groups should be closed for an initial period of three weeks. He wrote: ” I would recommend that schools should be planning on the basis that they may have to close for part or all of the pandemic.”

A Department of Health spokesman said contingency plans were being drawn up across Government. However, Sir David King, the Government’s chief scientific adviser, said he believed there was a “very low possibility” of a pandemic.