If their policies prove to be carnage they will be voted out at the next election. That's how it works. However, the short-term pain being felt by some now will hopefully be in the dim & distant past, if they successfully turn the economy around. I seem to remember Thatcher was hugely unpopular in her first few years (rightly so) but she managed to win two more terms. Hopefully, Starmer won't need a Falklands war though...