Votes referendum: Deputy PM Nick Clegg's speech in full
18 February 2011 Last updated at 14:18 GMT
The Deputy Prime Minister Nick Clegg has set out the case for changing the voting system for Westminster elections to the Alternative Vote.
Mr Clegg said the traditional first-past-the post-system ignored "millions of people".
In a separate speech, David Cameron argued that the existing system allowed voters to "turf out" unpopular governments.
They were setting out their arguments as campaigning began ahead of the 5 May referendum on voting reforms.