Ed Miliband branded Nick Clegg a vote-loser and refused to share a platform with him

Relations between Labour and the Liberal Democrats were back in the deep freeze yesterday after Ed Miliband branded Nick Clegg a vote-loser and refused to share a platform with him. Liberal Democrats accused Labour of "student politics" after Mr Miliband declined to appear alongside Mr Clegg at a rally to campaign for a Yes vote in the May referendum on electoral reform. Both leaders support a switch to the alternative vote (AV) and, despite Labour's anger at the Liberal Democrats for entering into a coalition with the Conservatives, figures in both parties who want to keep alive the prospect of a Lib-Lab deal after the 2015 election had hoped that co-operation on electoral reform might break the ice. Mr Miliband had agreed to share a platform with the former Liberal Democrat leader Charles Kennedy, but pulled out after Mr Clegg insisted on taking part. Today's rally has now been called off.

Labour is worried that a high-profile role for Mr Clegg could harm the Yes campaign, but their squabble is a setback for supporters of change.