Labour was the second biggest party in the House of Commons, with 243 MPs out of 650 seats, when Parliament was dissolved on 6 November.
Who is the leader?
Jeremy Corbyn. He is a 70-year-old former union official, and has been an MP for just over 36 years. He became leader in 2015 in a surprise election win. He had never previously been a government minister or held high office in the Labour Party. He has a loyal fan base as an anti-war, and anti-spending cuts, campaigner.
What does it need to do to win the election?
Labour needs to win 83 more seats than it had when Parliament was dissolved to form a government on its own, without having to seek a coalition deal with other parties.
Five key election pledges
The Labour Party launched its 2019 election manifesto, with the slogan It's Time For Real Change, on 21 November. It sets out the polices the party aims to introduce should it win the election.
Here are five key policies that appear in it:
- Increase the health budget by 4.3% a year
- Nationalise key industries, including the so-called big six energy firms, National Grid, and Royal Mail
- Introduce a £10-an-hour minimum wage for all workers
- Freeze the state pension age at 66
- Hold a second referendum on Brexit
Where does it stand on Brexit?
Labour wants to renegotiate Boris Johnson's Brexit deal and put it to another public vote. The referendum would be a choice between a "credible" Leave option versus Remain.
Under its Leave option, Labour says it will negotiate for the UK to remain in an EU customs union, and retain a "close" single market relationship.
This would allow the UK to continue trading with the EU without checks, but it would prevent it from striking its own trade deals with other countries.
It says it will achieve this within six months.
What else does it stand for?
Labour is a socialist party - that means it wants to tax the rich to pay for better public services, give workers more rights and take control of things like the railways, the Royal Mail, energy and water supply, so they are not run for private profit.
Labour's policies in a tweet
We will:— Jeremy Corbyn (@jeremycorbyn) November 6, 2019
✔ reduce NHS waiting times
✔ get Brexit sorted in six months
✔ kick start a Green Industrial Revolution
✔ build a million genuinely affordable homes within 10 years
We will end:
✔ in-work poverty
✔ food bank use
✔ rough sleeping
✔ tuition fees
How many members does it have?
According to the most recent figures, in July, Labour had 485,000 members.
What is the Labour Party's history?
Traditionally one of the UK's two main political parties, Labour was set up by trade unions nearly 120 years ago to give workers a voice in Parliament.
Since the end of World War Two, the UK has had a Labour prime minister for a total of 30 years, compared with 44 years for the Conservatives.