A hung parliament means that no single party has enough MPs to win parliamentary votes without getting support from members of other parties.

The largest party does not automatically have the right to form an administration and Gordon Brown has the right to stay in office as Prime Minister until a clearer picture emerges of which party or parties can command most support in parliament.

If Gordon Brown was to remain Prime Minister he would either seek to form a coalition with another party or parties or else he might seek agreements with other parties to form majorities for individual bills as they go through parliament.

However, with a larger number of MPs, David Cameron would also be looking at similar options.

This could potentially hand more power to the Liberal Democrats as they are courted by both sides. Nick Clegg could decide whether his party would be happy to support a minority government or seek a coalition with either the Conservatives or Labour.

With the Conservatives showing a clear lead in the polls it is possible that Gordon Brown could concede defeat and resign as Prime Minister. That could open the way for the Queen to invite the leader of the opposition, David Cameron, to attempt to form a government.

If no agreement is reached between any of the parties and no government finds itself able to get enough support to get the Queen’s Speech through parliament by May 25 that would force a second, early general election.