The debt and 'endless austerity' is somewhat overhyped, yes there is a huge public sector pension burden, but that is spread over nearly 50 years and I'm sure if you had quoted the pension liability to someone back in the 70s, they would have been just as astounded as we are today. Moreover, as the post-war baby boom generation begin to die off over the next 2 decades, the burden on the state will actually ease slightly. Housing benefit is another example of a huge expense that has ballooned out of nowhere over the last few years, but there is now a cross party consensus that the housing market needs to be flooded with new homes, which will relieve the cost of rents, so that is an expense that is likely to subside over the long term.
The big headache is health as its demand is increasing and the costs of healthcare provision keep increasing exponentially...however, I think it's inevitable that some form of co-payment is going to be introduced for things like visiting your GP.
I'm going to reiterate a point I make quite a lot, there is money for the core government responsibilities, and there always will be, we just choose to spend such vast amounts on other things that the electorate has come (rather unreasonably, in my opinion) to expect from the government i.e. free TV and transport for every single pensioner WTF?