during a division, suggesting that some of the rules governing parliamentary procedure are violated, he was required to wear a hat, thereby signalling that he was not engaging in debate. Collapsible top hats were kept in the Chamber just for this purpose. This custom was discontinued in 1998. The outcome of most votes is largely known beforehand, since political parties normally instruct members on how to vote. A party normally entrusts some Members of Parliament, known as whips , with the task of ensuring that all party members vote as desired. Members of Parliament do not tend to vote against such instructions, since those who do so jeopardise promotion, or may be deselected as party candidates for future elections. Ministers, junior ministers and parliamentary private secretaries who vote against the whips' instructions usually resign. Thus, the independence of Members of Parliament tends to be low, although "backbench rebellions" by members discontent with their party's policies do occur. A member is also traditionally allowed some leeway if the particular interests of his constituency are adversely affected. In some circumstances, however, parties announce " free votes ", allowing members to vote as they please. Votes relating to issues of conscience such as abortion and capital punishment are typically free votes. Pairing is an arrangement where a Member from one party agrees with a Member of another party not to vote in a particular division, allowing both MPs the opportunity not to attend. [6] [7] A bisque is permission from the Whips given