A procedure by which the parties may object to the composition of a jury before it is sworn. Formerly, a challenge could be peremptory (with no reason for the challenge being given) or for cause. Peremptory challenges were abolished by the Criminal Justice Act 1988, but in some circumstances the prosecution may be entitled to ask that a juror “stand by” as he is about to take the oath. This is usually where either (a) the defence agrees with the prosecution that a juror is totally unsuitable or (b) the Attorney General has ordered a security check on the jury in a case involving terrorism or national security. Either party may challenge for cause. This may be to the array, in which the whole panel is challenged by alleging some irregularity in the summoning of the jury (such as bias or partiality on the part of the jury summoning officer); or to the polls, in which individual jurors may be challenged. A challenge for cause is made immediately before the juror is sworn, and may be made on the grounds that the juror is not qualified to serve or is biased. Any challenge to jurors for cause is tried by the trial judge.