What makes us change our mind when it comes to elections? We are all swingers now. More voters than ever before are switching party from one election to the next. Tribal loyalties are weakening. The electorate is now willing to vote for the other side.

Professor Rosie Campbell from Birkbeck University finds out what prompts voters to shift from one party to another. Quentin Davies had been a Tory MP for decades when he crossed the floor of the house. He believes his views stayed the same - but the world changed around him. Journalist Janet Daley was once too left wing for the Labour Party - until Margaret Thatcher came along. Meanwhile Daryll Pitcher felt as though no party wanted his vote. Today he is a UKIP campaign manager.

Does age make us become more right wing? Have the main political parties alienated their core vote? And what does this mean for democracy?

Producer: Hannah Sander.