Yep; I think the above comment took the wrong lessons.

What actually happened in the US is that "common norms and expectations" were thrown out the window, so instead of the question being "What is traditionally done?" it became "What can legally be done?" And, as it turns out, when you're only constrained by the letter of the law the executive branch is insanely powerful.

UK politics, more than most younger countries, is particularly susceptible to this. Norms, traditionally, and commonly understood standards make up a scary amount of constraints on the powers of government. If anyone gained power that only feels limited by the letter of the law (i.e. throws out norms, traditions, and standards), the UK is in serious trouble and Parliament hasn't moved to address it.

Somewhat ironically (given how unpopular it is), the Lords may be the best back-stop the UK has. Particularly the 30%~ which do not originate from politics.