In British politics there is a whipping system to ensure that MPs attend votes and also vote as their party wishes them to. Most large parties will have a Chief Whip, Whips and Assistant Whips. The Government Chief Whip has an official residence at 9 Downing Street.
At the beginning of the week each Chief Whip will send out an agenda to all MPs and Peers in their party, this is also called a whip. The Whip will mark all debates in which the MPs' attendance is essential and underline it one, two or three times, depending on how urgent it is for them to attend. Items underlined once have optional attendance, twice are considered more important but a "pair" can been arranged. This is when a member of the Opposition will also agree to be absent to balance out your absenteeism. Items underlined three times are extremely important, attendance is mandatory and no pairing can be allowed.
The penalty for disobeying the whip can be harsh and, theoretically, the punishment for disobeying a three-line whip can be expulsion from the party. If you are a minister, you will be immediately returned to the backbenches. On some votes the whips will be removed, as they are considered a matter of conscience, such as religion or equal opportunities.
Whips never speak in public about their role and therefore it is seen as a rather mysterious and murky part of politics. Whips are often portrayed as machiavellian and one MP recalls a story of Whips bringing an MP who had just suffered a heart attack to the House in an ambulance so he could vote.