Where do you stand on that know? Would you be willing to take a substantially lower interest rate in a UK based account over a foreign, more ambiguously guaranteed one?
Would probably still trust FSCS upto it's stated limits (although I would reread/print relevent bits from their website and might do research before investing in Icelandic, Greek, Cypriot and maybe even Italian banks to check there is no risk of devaluation and default that isn't covered.