How much difference have the Lib Dems really made?

Here is an interesting thought: is it possible that the Liberal Democrats' position in the coalition has succeeded in neutering the worst aspects of Conservative policy making?

Take the NHS. It is arguable that, if it wasn't for the revolt at the Lib Dem conference in late 2010 and resultant effect on the positions of the Liberal Democrat leadership on this issue, that the Tories may have tried to ram through Lansley's proposals without amendments. Of course, it is also arguable that the massive opposition from doctors' groups, nurses and other health professionals would have had the same effect anyway, but it is an interesting debate.

And what about the recent attempts by Christian groups to take abortion advice off abortion providers. Did the Lib Dem's persuade Cameron to change his mind? The right-wing press clearly thinks so.

And, most recently, how about Clegg's claims that he managed to defeat Michael Gove's attempts to allow Free Schools to turn a profit come a second term of a Tory government.

Now, there is the counter-argument: that despite all this, the Liberal Democrats, in conceding to the largest public spending reductions in modern times, have capitulated on the most important issue and handed the Tories the opportunity to provide cover for their economic decisions.

Furthermore, it is easy to list a range of areas - including higher education reform (including tuition fees), EMA and, in fact, the existence at all of the NHS 'reform' programme - where the Liberal Democrats have needlessly agreed to support proposals that were in neither the blue nor yellow manifestos.

Nevertheless, it is an interesting thought: could it be much worse. And, equally intriguingly, if it is Lib Dem influence that has tempered many of these decisions, does it demonstrate how shallow Cameron's so-called moderate convictions really are?