So … Prince Charles and Camilla will be rueing going to the theatre in black tie, with the car all lit up. Their security advisors will be going over how it happened and, as ever when it comes to the policing of protests, the police will be damned if they do and damned if they don’t.

David Cameron will be wondering how a relatively tame environment for his government has suddenly turned so nasty, with so many people – even if it is true that only a minority were hellbent on violence – feeling so passionately opposed that they take to the streets in this way.

And Nick Clegg will be left wondering how he has gone from hero to zero amongst the younger voters of Britain quite so quickly.

One word of warning to him – once an MP rebels for the first time, it becomes easier to do it a second time, and the pressures always to rebel become stronger. Likewise, once people think a protest is only a protest if there is violence attached to it, that risks becoming a habit too, and the new coalition government, so comfortable with itself, comes to see the country is not at ease with ITself.

But for Labour, there are risks too, and one is the extent to which the Lib Dems have become ideological human shields for the Tories. You may remember the other day I asked when was the last time David Cameron, George Osborne, Michael Gove or David Willetts were out there really having to defend their policies? Even today, it is still the Lib Dems who are feeling the greatest heat, and the media seem to find divisions within the minority coalition partner more interesting than the actions of the big boys.

The tuition fees issue has particular potency for the Lib Dems because of the specific pledges they made. But it is helping the Tories that so much of the heat is deflected onto the junior member of the coalition. The Tories have managed the politics of this too well, and when it comes to the cuts, they not the Lib Dems need to feel more of the heat.

Labour have known for a long ime at local level what irritants Lib Dems can be, and many in our ranks will be enjoying the sight of Clegg, Cable, Alexander et al squirming all  over the place, and suddenly finding that government is a lot tougher than opposition.

But we should never lose sight of the fact that this is a Tory government driving a Tory agenda in the hope of recreating a Tory Britain. So the Lib Dem human shield is more useful to the Tories than it is to Labour, and it is the Tory ministers we need to see more of as the public make a judgement on what is going on.