The purdah period typically begins six weeks before the scheduled election, in each authority on the day the notice of election is published; for the 2015 General and local elections purdah will begin on Monday 30 March.
Purdah has been imposed in ministerial guidance since at least the early 20th century reflecting an earlier "self-denying ordinance", and has considerable moral authority, its breach carrying with it in worst cases the possibility of actions for abuse of power and misconduct in public office. Otherwise its lack of statute or common law means different local authorities adopt different standards as to the extent to which they observe the convention, and executives are always mindful of the possibility of decisions being open to judicial review on the grounds of legitimate expectations, breach of natural justice, or procedural impropriety if purdah is breached. Where observed by executive officers purdah bars entering into any transactions or carrying out any works which would clearly, directly conflict with thestated intentional commitments (manifesto) of the cabinet or shadow cabinet in any authority. When local elections are being held at the same time as a general election this higher standard is usually applied.
At the national level, major decisions on policy are postponed until after the purdah period, unless it is in the national interest to proceed or a delay would waste public money. The Cabinet Office issues guidance before each election to civil servants, including those in the devolved national parliaments and assemblies. Purdah also continues after the election during the time in which new MPs and ministers are sworn in. In the event of an inconclusive election result, purdah does not end until a new government forms. When no party has an overall majority, it may take some time before a minority or coalition government is formed.
Section 2 of the Local Government Act 1986 prohibits the publication by local authorities of material which in whole or in part appears to be designed to affect public support for a political party.
………………I had never heard of this saying, until I started to work in a department with council workers and they kept going on about it. I don't think it applies to police as we should be impartial at all times.