Some will say - at last! - deep cracks are forming in the coalition government. The issue was not the decision to raise VAT or slash public sector workers or treble student fees. No, the issue was Europe. Traditionally, Europe has been the issue that most divides the Conservatives and there are divisions to be found between many pro-European ministers, principally Ken Clarke, and Eurosceptic backbenchers. The fireworks on display over the Prime Minister's recent "veto" were not - perhaps surprisingly - on display between Tory MPs, but fired by Eurosceptic Tories at their Liberal Democrat coalition "partners". No wonder Deputy Prime Minister, Nick Clegg, (in an "unprecedented" move) missed the session: it's bad enough facing angry voters and angry opposition benches, but also most of the party with whom your party is in coalition? It's almost too much.
While many will point to the principled stance of Liberal Democrats (finally?) reasserting themselves in the coalition, there is perhaps another explanation for the sudden unease: one new poll has put UKIP ahead of the Liberal Democrats. If true, then perhaps a strong incentive for Lib Dems to speak out now -- instead of before on Trident, VAT, university fees, etc. -- is not mere survival after the next general election, but the possibility -- however faint -- that the Lib Dems may no longer the main alternative to Labour and the Conservatives. Lib Dems were always going to have difficulty differentiating themselves in future elections given their position in the coalition and UKIP may be benefitting.
Of course, it's all too early to tell. But, if you're a Liberal Democrat, it may not be too early to begin to panic.