Andrew Cooper, spokesman for CLIC charity says half of all children, who are off school while receiving treatment don't get enough support and contact from their teachers.
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Parents have said they are pulling their children out of school for the day in strike action against the government.
A phone line mix-up has caused chaos in a village - after residents were left with their neighbours's numbers.
Among the cyclists is Andrew Venn whose son Joe has a congenital heart condition and will need hospital treatment all his life.