There is no deadline for bringing an appeal to a polling place review.
It can be brought at any time after the completion of a review. However, the Commission will not (other than in exceptional circumstances) make any decision on an appeal affecting an election between the notice of publication of that election and polling day.
It also ought to be noted that the time taken to complete a review varies, but can take several months, so there can be no guarantee that bringing an appeal at any particular point prior to this will result in a decision affecting a forthcoming election.
The Commission publishes details of previous appeals and Commission decisions, on our website. It also publishes the appeal documents.