Limited the price cap

Oh, come on. For a lot of people the energy prices may as well be £1,000 p/m for as good as it does them.
£150 isn't nothing, you're right. It's a slap in the face and, what's that term you keep using... A short term solution.
I don't know why you're just throwing all short term solutions together as if they somehow correspond.
As we stand today there are millions of people unable to afford to live on a basic level whilst oil companies are showing unheard of profits.
I'm not sure how the outcome of taxing them more/a windfall tax could be worse than the British public literally starving and freezing - which they are doing.
Maybe they could be starving and freezing and sat uncomfortably.