A hung parliament is when no political party has an overall majority of seats in the House of Commons.
To have a majority a political party has to have more than half of the 650 seats in the House of Commons, and therefore more seats than the combined opposition parties.
This is Britain's first hung Parliament since 1974.
Find out more about hung parliaments
What happens now?
The House of Commons Justice Committee released a report in March 2010 based on evidence it heard that, in light of speculation that the general election could result in a House of Commons where no one party has an overall majority, looked at how constitutional principle, provision and practice apply after general elections.
Report: Constitutional processes following a general election
The Cabinet Office has published draft guidance on elections and government formation, including procedures that would take place in a hung Parliament situation.
The Cabinet Office (external site)
The House of Commons library has issued a Standard Note that looks at the situations where there has been no overall control in the House of Commons during the twentieth century. It considers precedents and conventions governing how the monarch might decide which party should form a government in such a situation, and when a request for a dissolution might be granted.
Topical Issues: General elections
Image: Parliamentary copyright