The reason why SSF have failed on LIFFE is because in Europe they have CFDs (contracts for Difference), basically trading on 5 and 10-1 margin, with the liquidity coming straight from the cash market.
Basically if I buy 10,000 Vodafone at £1.00 the CFD broker will trade for me on the cash quote, charge me say £2k in initial margin and loan me the rest, with of course variation margin to pay if need be.
CFDs are pretty much a con because yes you get the leverage but then the commission is on the nominal amount. Say for example I buy 1 FTSE futures contract at 4000, nominal amount £40k with a commission of say £3 or 0.0075%. If I buy £40k of stock on a CFD, I'll likely be charged at best 0.1 or £40, and that's a big difference.
