Election debate: Johnson and Corbyn clash over Brexit - BBC News
Nearly 7 million people watched leaders lock horns over the NHS in the first TV debate of the election.

• Term for an MP who is not a minister. They sit behind the front benches in the House of commons.
• A sealed box with a slit in the lid. Voters place their ballot papers through the slit into the box. When polls close the boxes are opened and counting begins.
• Paper containing a list of all candidates standing in a constituency. Voters mark their choice with a cross.
• An election held between general elections, usually because the sitting MP has died or resigned.
• Someone putting themselves up for election. Once Parliament has been dissolved, there are no MPs, only candidates.
• During a campaign, active supporters of a party ask voters who they will vote for and try to drum up support for their own candidates.
• The deadline for candidates standing to send in the officials forms confirming their place in the election. This is usually __ days before polling day.
• When two or more parties govern together, when neither has an overall majority. After the 2010 election, the Conservatives and Lib Dems formed a coalition, which lasted for five years.
• A agreement between two political parties where the smaller party agrees to support a larger one without enough MPs to have a majority in parliament.
• The geographical unit which elects a single MP. There are 650 in the UK.
• In politics, a 'dead cat' strategy is when a dramatic or sensational story is disclosed to divert attention away from something more damaging. The term comes from the concept of an imaginary dead cat being flung onto a dining table, causing the diners to become distracted by it.
• The announcement of the election result in each constituency.
• A sum of £500 paid by candidates or their parties to be allowed to stand. It is returned if the candidate wins 5% or more of the votes cast.
• The delegation of powers to other parliaments within the UK, specifically the Scottish Parliament and Welsh and Northern Ireland Assemblies.
• The Scottish Parliament and Welsh and Northern Ireland assemblies are elected by voters in those nations of the UK. They make laws on policy areas controlled by those nations such as health, environment and education.
• The act of ending a Parliament before an election. When parliament is dissolved there are no MPs, but the prime minister and other senior ministers remain in their roles.
• A list of everyone in a constituency entitled to vote. Also known as electoral roll.
• An exit poll is a poll of voters leaving a voting station. They are asked how they have voted, and the results are used to forecast what the overall result of the election may be.
• Term used to describe the UK's parliamentary election system. It means a candidate only needs to win the most votes in their constituency to win the seat.
• When a party wins a constituency from another party, it is said to have "gained" it from the other.
• Election at which all seats in the House of Commons are contested.
• If after an election no party has an overall majority, then parliament is said to be "hung". The main parties will then try to form a coalition with one or more of the minor parties. Opinion polls have suggested that a hung parliament is a strong possibility after the 2015 general election.
• A meeting a which candidates address potential voters. The word comes from an old Norse word meaning "house of assembly".
• A candidate who is not a member of any political party and is standing on their own personal platform. To qualify as an official political party, a party must be registered with the Electoral Commission, the organisation which administers elections in the UK.
• The name given to an election which one party wins by a very large margin. Famous landslides in UK elections include Labour's victory in 1945, the Conservative win in 1983 and the election which brought Tony Blair to power in 1997.
• A person or party with strong socialist policies or beliefs.
• The name of the party occupying the centre ground of British politics. They were formed from the former Liberal party and Social Democrats, a Labour splinter group, and combine support for traditional liberalism such as religious tolerance and individual freedom, with support for social justice.
• A majority in Parliament means one side has at least one more vote than all the other parties combined and is therefore more likely to be able to push through any legislative plans.
• When one party wins more than half of the seats in the Commons, they can rule alone in a majority government
• Politicians say they have a mandate, or authority, to carry out a policy when they have the backing of the electorate.
• A public declaration of a party's ideas and policies, usually printed during the campaign. Once in power, a government is often judged by how many of its manifesto promises it manages to deliver.
• Seats where the gap between the two or more leading parties is relatively small. Often regarded as less than a 10% margin or requiring a swing (see below) of 5% or less, though very dependent on prevailing political conditions.
• A minority government is one that does not have a majority of the seats in Parliament. It means the government is less likely to be able to push through any legislative programme. Boris Johnson has suffered a number of defeats in Parliament over a no-deal Brexit because he does not have a majority.
• Strictly this includes members of the House of Lords, but in practice means only members of the House of Commons. When an election is called Parliament is dissolved and there are no more MPs until it assembles again.
• A candidate must be nominated on these documents by 10 voters living in the constituency.
• A survey asking people's opinion on one or more issues. In an election campaign, the key question is usually about which party people will vote for.
• The largest party not in government is known as the official opposition. It receives extra parliamentary funding in recognition of its status.
• Broadcasts made by the parties and transmitted on TV or radio. By agreement with the broadcasters, each party is allowed a certain number according to its election strength and number of candidates fielded.
• The swing shows how far voter support for a party has changed between elections. It is calculated by comparing the percentage of the vote won in a particular election to the figure obtained in the previous election.
• Place where people go to cast their votes
• People unable to get to a polling station are allowed to vote by post if they apply in advance.
• Any voting system where the share of seats represents the share of votes is described as proportional representation. The UK currently has a first past the post system.
• Parliament is usually prorogued, or suspended, ahead of an election or Queen's Speech to allow for preparations. In September 2019 Boris Johnson attempted to prorogue Parliament for five weeks, but the Supreme Court later ruled the prorogation unlawful and MPs returned to Parliament.
• This is the time between the announcement of an election and the final election results. During this period media organisations have to ensure any political reporting is balanced and is not likely to influence the outcome of the election.
• If a result is close, any candidate may ask for a recount. The process can be repeated several times if necessary until the candidates are satisfied. The returning officer has the final say on whether a recount takes place.
• The official in charge of elections in each of the constituencies. On election night they read out the results for each candidate in alphabetical order by surname.
• Someone who is right wing in politics usually supports tradition and authority, as well as capitalism. The Conservative party is regarded as the main centre-right party in the UK.
• A safe seat is a constituency where an MP has a sufficiently large majority to be considered unwinnable by the opposition.
• The attempt to place a favourable interpretation on an event so that people or the media will interpret it in that way. Those performing this act are known as spin doctors.
• Any ballot paper that is not marked clearly, eg with more than one box ticked or with writing scrawled across it, is described as a spoiled ballot and does not count towards the result.
• This is when people vote not for the party they really support, but for another party in order to keep out a more disliked rival.
• In theory, any seat that a party contests and held by a rival is one of its targets. In practice, a target seat is one that a party believes it can win and puts a lot of effort into doing so.
• Turnout is the percentage of eligible voters who cast a ballot on polling day.
• It is usually the leader of the opposition, currently Jeremy Corby, who calls for a vote of no confidence, in an attempt to topple the government. If more MPs vote for the motion than against it, then the government has 14 days to try to win back the confidence of MPs through another vote – while the opposition parties try to form an alternative government. If nothing is resolved, then a general election is triggered.
• The UK Parliament is located in the Palace of Westminster in the centre of London and the term is often used as an alternative to Parliament.
• A working majority in Parliament is what a government needs to carry out its legislative programme without risk of defeat. It means the government can rely on at least one more vote than the opposition parties. However, in the current Parliament, the government no longer has a majority and MPs from a range of opposition parties have joined forces to form a parliamentary majority big enough to defeat the government over plans for a no-deal Brexit.