Election 2015: Talk turns to post-election government
Labour's Ed Miliband has suggested he would rather not become prime minister than do a deal with the SNP to be in government.
Nicola Sturgeon said it showed that Labour had lost the plot. The Scottish Conservatives said a Labour minority government would be a disaster.
The Scottish Liberal Democrats said only their party can hold the centre ground and bind the others together.
BBC Scotland's political correspondent Tim Reid reports.