The UK? The birthplace of neoliberalisn, of privatisation of "health care"? Give me a break. I'm not even going to question or look up your "official data", I'll just point and laugh. Do something about it.
These are my graphs of the data.
[IMGW=840]https://pbs.twimg.com/media/FD5drg-XEAEGyA7?format=jpg&name=large[/IMGW]
This shows the recorded all-cause deaths in England and Wales in 2020. It also has the death certificate data for then.
Now you'd have to be a completely stupid conspiracy theorist to think that coroners offices throughout the country made up deaths or that the ONS invented deaths in order to make the government look bad. You'd need thousands of doctors to cooperate in a criminal enterprise for no benefit to themselves.
I do know that at least one antivaxer might have had an explanation for how lockdowns or vaccines caused these deaths before they started but I guess you'd think that was stupid too:
[IMGW=320]https://pbs.twimg.com/media/E_wZR1UVgAIddL9?format=png&name=small[/IMGW]
So, ignoring time-travelling nanopatticles, you have Covid deaths being undercounted by about 2000 deaths per week for the 5 weeks of the first wave based on a simple eyeballing of the data (actuaries tend to estimate about 12000 in total, which is consistent)
There are plenty of non-nefarious explanations for this undercounting. A lack of testing and a lack of familiarity with the symptoms at the time are the most obvious.
ETA: Your rejection of the data makes no sense. This is not really the NHS but, hey, poison the well
We could look at other multiple other countries and see similar situations - however the UK does have some of the highest-quality data easily available