I mean your subjects are fine, I would just recommend avoiding LSE for single subject economics and probably Cambridge, possibly UCL, just to be on the safe side. Warwick are relatively clear that it's not preferred over other subjects, and for PPE at Oxford maths is perfectly sufficient. Note that for joint honours courses in economics at LSE where the other half is a non-mathematical subject (e.g. politics & economics, philosophy & economics, conomics and economic history, possibly PPE) FM is not essential. There are also plenty of good economics courses elsewhere e.g. Bristol, Manchester, Nottingham etc.
If you really want to apply to LSE for single subject economics then you could look at doing FM in a gap year. However if your reservation is that you are not that keen on maths then you definitely have more things to consider as economics is necessarily mathematical at degree level. So if you don't like maths then that might be a sign economics is not the right degree for you.
Of course if you're interested in economic phenomena and concepts as they apply in various situations, there are other courses that will incorporate elements of that; economic policy will be considered in politics/IR courses in various ways I imagine for example, economic history perspectives will come up in most history courses (and especially in specialist economic history degrees like the one at LSE), some aspects of microeconomics are relevant to and come up in courses in e.g. finance/business/management, etc. Anthropologists and archaeologists may be interested in how economies developed in both historical cultures and in modern cultures which may not align with Western capitalism and associated values (e.g. hunter-gatherer societies, gift economies, and communist/postcommunist societies).