JTC: I use C i t y I n d e x for cfds and find them extremely good. They do spread betting but I have never indulged yet; this may change this year. Market capitalisation of the company needs to be over 25 million for cfds but very illiquid stocks are on lesser margin. Normal margin 10% but IEC and JKX for instance are 5%. As pointed out by coco shorts pay small interest.
As to the ethics of shorting I have no qualms in the least. The anti shorting vocals seem to eminate from a large selection of small private retail investors on the bulletin boards who have no facility to short. The ethics of going long are exactly the same as going short in my opinion: you decide on the market direction and you put you money accordingly: we have no power to turn the market.
JTC and HB: any view on JKX chart and/or fundamentals and/or politics. The overnight Belarus settlement bodes well for JKX this year especially since Gazprom hegamony has now settled down in the Ukraine where JKX's income is mostly derived.