Howard #49
Firstly, there is The Separation of Powers:Executive;Legislative;Judicial
https://en.wikipedia.org/wiki/Separation_of_powers#United_Kingdom
Secondly, The Supremacy of Parliament. Except for the EU and the hundreds of letters, advisory and instructional, that emanate from the foot of the Mall.
By the by, We have Anti-Terrorism Legislation - go explain that to Iceland. We also have a 'snoopers charter' that was to be of great help to us, but as a tool in the box of Local Government it was not left idle long.
Such things should not be messed with to avoid tabloid headlines and/or to pander to the 'Little Englanders'.