Britain is the only country where austerity is still taken seriously, and it's because the right have made it part of the narrative of "fairness" and "in it together". Hence drastic cuts when elected, that are sneakily put aside soon after.
The only country? I guess you haven't been reading the European news.
Angela Merkel introduced in 2011 the largest cuts ever seen in Germany since WWII and of course the Germans are a well known advocate of austerity througout the Eurozone.
Recently, the Germans amended their constitution which makes a Federal Government structural deficit of 0.35% of GDP illegal from 2016, and will also forbid State Governments running a structural deficit from 2020. For comparison the UK has a structural deficit of around 3% of GDP IIRC.
Prior to Frau Merkel, centre-left Gerhard Schroeder introduced austere welfare measures, to boost German competitiveness (Hartz IV reforms) in the mid 2000s. The UK is embarking some years later on similar reforms with the (delayed) introduction of Universal Credit.
Away from Germany, the Finnish Government have been the greatest advocates of austerity in the Eurozone for the past few years. After the recent general election the new government is intending to be even more austere.
So Britain is certainly not the '
only country where austerity is still taken seriously.'