Contempt is something that interferes with Parliament or obstructs it, or a member of either House, from performing their duties. It is loosely defined, and Parliament decides whether something is or is not contempt. It has in the past included criminal acts, misleading the House, financial misconduct, leaking parliamentary proceedings. It can also include obstruction, such as not obeying a direct command by the House.
Yes. Both non-members and members of the House can be found in contempt. This can include individual ministers or a number of ministers as representatives of the Government.
There have been a number of cases of ministers resigning after being accused of misleading the House but before any contempt proceedings were laid against them. The contempt motion on 4 December 2018 was the first time ministers have been found to be in contempt in modern parliamentary history.
Usual practice is for a member to raise the issue with the Speaker. They might ask that it be referred to the Committee of Privileges or the Committee on Standards, or table a motion. If it is referred to a committee, it then decides if a contempt has been committed and reports to the House. This is then debated and the House decides whether to follow the recommendations. If it is a motion, then the House can decide itself.
Parliament can order the Government to a course of action. However, its powers to force action are limited to threatening ministers with even greater punishment.
Parliament’s powers to punish contempt are quite weak. The 4 December 2018 motion did not require any further punishment.
Parliament used to be able to imprison or fine perpetrators, as a court of law, but these powers have lapsed. The last time Parliament fined someone was in 1666, and the last time it imprisoned anyone was in 1880 (in the Clock Tower). There have been many calls to put the ability to fine on a statutory basis. Most punishments on non-members involves bringing them before the House to be reprimanded.