There have been numerous critics of austerity measures - they are simply not effective economic strategies at the moment. For the economy to recover, it needs to grow. For it grow, more money needs to be spent - which for your average person just isn't a rational thing to do at the moment. Govts need to invest if they want the economy to grow.
It so happens that people like Osbourne have managed to convince everyone that debt in the UK is so utterly catastrophic that any public spending is utterly unthinkable. Debt at the moment is hardly desirable, but it isn't nearly as bad as austerity proponents say it is. Here is a graph depicting British govt debt over time:
http://krugman.blogs....british-debt-history/
While it's not ideal, it's certainly not anything like as catastrophic as the govt. is leading people to believe.