It isn't just a British problem, though
Of course not, but the
'Mother of Parliaments' leads the way.
We know, that in almost in any country around the world
(including those claiming to be a democracy) the 'ruling class' and/or their hangers on, get away with the "Don't do as I do, do as I say" Mantra, it is what keeps them 'in-situ' in these so called 'democracies', because if you don't like them you can vote them out at GE's... in theory at least! The trouble is the next lot is just as prone to the same Mantra, maybe they are at the opposite end of the political spectrum, but its still "Don't do what I do do what I say" (.e.g Labour Politicians who deride private/fee paying schools, but send their own children anyway).
At least in a country with a Strong man/Dictator figure, who retains power through the use of force, you know what to expect; what upsets people in what they believe is a democracy, is when that mantra is clearly seen to be in use, (
as recently in 'partygate') because they don't think it should be, it annoys their sensibilities, because they believe they live in (
for the most part) a liberal democracy.
However in a democracy, or any other system of government, those in power will always follow the "Don't do as I do, do as I say" mantra' and for the most part they get away with it, even against a background of a pandemic.
Even a constitution that was written down wouldn't solve this problem, but it would make it a dam sight more difficult to get away with it.