I would have thought that campaigning on the platform of being the ones who will hold the balance of power after the election would boost their performance. You also claim that you will act as a moral and ethical watchdog for the people, keeping an eye on your coalition partners. It's generally a real vote winner.

Especially as Clegg has said that they would be willing to support a minority government for certain key policies going through. Why not enter a formal coalition, you negotiate a common programme for government stating what policies are to be followed and you also get a couple of portfolios around the cabinet table. If things are going badly you just pull the plug and bring down the government.

In the Irish experience the minority partners in a coalition get major influence because the bigger partner wants to be in power so much they will make large concessions.