Purdah is the term used to describe the period between the time the election is announced and the date the election is held. It is now often referred to as the pre-election period. Civil servants are given official guidance that decisions on policy on which a new government might be expected to take a different view from the present one should be postponed until after the election. This is always provided that such delay would not be detrimental to the national interest or wasteful of public money.
Further information on this subject can be found from the following link.
Library Standard Note 5262: Purdah, or the pre-election period (
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