Vote 2011: Clegg fights back with NHS pledge
Nick Clegg has promised "a louder Lib Dem voice" in government and says he will show the party is "a moderating influence on the Conservatives".
He told Andrew Marr he was expecting "significant changes" to the planned NHS overhaul and would block the legislation unless he was personally happy with it.
You can watch the Andrew Marr Show in full on the BBC iPlayer