Deputy PM Nick Clegg launches push for AV yes vote

Nick Clegg has set out his views in support of the Alternative Vote system, as the 5 May referendum campaign got going in earnest.

The deputy prime minister said that under AV MPs would be forced to work harder to earn and keep their seats.

He also argued that the current system "made corruption more likely".

Prime Minister David Cameron is later expected to argue in favour of keeping the existing first-past-the-post system, saying that it provides decisive results and accountability.

How the Alternative Vote system works