Each item of business that MPs consider in the Commons – be they motions or pieces of legislation – is framed in terms of a question. At the end of a debate, that question is “put” by whoever is chairing the debate (usually the Speaker) to MPs.
At first, MPs indicate whether they agree or disagree by shouting “aye” or “no”, when invited to by the chair of the debate. If one side is clearly louder than the other, and it is clear what the position of MPs is, then the Speaker declares that either the ayes or the noes “have it” – in other words, that that particular side has won. This is known as voting “on the voices”.
But sometimes, if shouts of the ayes and noes are evenly matched, and it is not obvious what the position of MPs is, then the Speaker will call for a “division” – the parliamentary term for a formal vote.
Divisions involve MPs casting a vote by physically walking down one of two corridors on either side of the main Commons chamber: either the “aye” lobby or the “no” lobby. In this sense, the House literally divides.
The Speaker announces a division by shouting “clear the lobby”. A system of bells will ring across the entire parliamentary estate so that MPs who are not in the chamber but may be in other parliamentary buildings know there is a vote. MPs have eight minutes to make it to the lobbies to ensure that their vote will be counted. After eight minutes, the doors to the lobbies will be locked, and MPs will not be able to get in to cast their vote.
Meanwhile, the Speaker will put the question to MPs again, just two minutes after first putting it, to ensure that MPs still want to press the matter to a division. At this point, four tellers must be appointed. Tellers are MPs (usually whips) who stand in the division lobbies and count the votes. There are two tellers for the ayes, and two for the noes. If no tellers can be found for one side, they automatically are judged to have lost the vote.
MPs then walk through either the aye or no lobby, where their name is recorded by three clerks – members of the parliamentary staff. Once all MPs in each lobby have gone through and had their votes recorded, the Speaker is informed that the lobbies are clear.
The tellers then return to the Commons chamber and inform the parliamentary staff of the result. All four tellers line up at the table in the chamber, and then step forward to read out the result of the division to the House. It is convention that the tellers for the winning side stand on the left-hand side of the Speaker – meaning that even before the exact results are read out, it is possible to know which side has won.
There is no formal way for an MP to register an abstention. However, if an MP walks through both the aye and the no lobbies, their votes are recorded but do not count – and this is usually understood to mean that the MP is abstaining.
It depends. All voting is done in person: there is no means for MPs to vote electronically. Historically, MPs who have been unwell, away on visits, or had family emergencies had to rely on the pairing system. This was an informal system, by which party whips found MPs on both sides who were unable to vote and paired them with one other. This meant that their inability to vote was cancelled out and didn’t change the numbers – though they didn’t have any vote actually recorded.
Since January 2019, MPs on baby leave have been able to cast their vote through proxies – other MPs who vote on their behalf. Proxy votes are indicated on the division lists published after each vote, which set out how every MP who voted.
First, MPs are not obliged to vote in each division – though their parties may whip them to do so.
Second, some MPs are ineligible to take part in votes. This is the case for the Speaker (unless the vote is tied, in which case the Speaker exercises the casting vote), the three deputy Speakers, and the four MPs who act as tellers on a vote.
Any MPs who are elected to Parliament, but choose not to take up their seat, are also forbidden from voting. That means that the seven Sinn Féin MPs do not vote, as historically that party does not take up its seats in the Commons.
This means that the number of votes cast in a division is never actually be equal to the number of MPs (650).
It can vary, but each division in the Commons usually takes around 15 minutes.