(Chiefly British:) A period before a decision (such as a new regulation) takes effect, during which opposed opinions are heard.
A consultation usually takes place after an unpopular resolution has been made by the authorities. Usually a consultation offers the illusion that people's opinions matter and that said decision can change, where in fact they are merely designed to let steam out.
Consultations also 'cover the decision maker's arse': when the decision turns out to be a mistake, the absence of public records of the consultations allows the decision maker to claim to share the responsibility.
The announcement of budget cuts was followed by a brief consultation, during which everyone chickened out and nobody spoke up.