Voting in the European Parliament is unlike decision-making in any of the UK's domestic democratic institutions.
The parliament holds a daily voting session for around an hour at lunchtime, with MEPs often having to vote on hundreds of amendments in succession, meaning that the session is rapid and confusing.
Each issue being voted on has usually been debated the previous day.
Decisions are usually taken on an absolute majority of votes cast, as long as there are a minimum of a third of MEPs present - known as the quorum.
If there are fewer MEPs present than the quorum, the vote is delayed - it is held the next sitting day.
The most basic voting procedure in plenary is a show of hands. However if the President is unable to determine a majority from this, he or she will call for an electronic vote to secure an exact result.
If requested by a political group or at least 40 MEPs, a roll call vote may also be taken, which sees the individual vote cast by each MEP recorded and published in the minutes of proceedings.