The Discovery New School in Crawley is to close.
Lord Nash, the Parliamentary Under Secretary of State for Schools, has written a letter to the school to say he is "not satisfied that the action the Academy Trust proposes to take is sufficient in all the circumstances."
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Schools in London, Brighton and Newcastle were among those closed after bogus security threats.
Minh Quang Pham was sentenced in a US court for three counts of terrorist-related activity.
Simon has Saturday's forecast for the east of the region