Options are... #1 - As stated :-) #2 - Extension supplied by 1-gang RCD protected 13A fused spur. Can not recall the price, =A315-22, check backbox depth required. #3 - BS8436 cable, which is about =A31.50-2.00 per metre, 100m reels as TLC do not carry it.
Impractical options #4 - Armoured cable is out unless glands are left exposed for inspection & testing. #5 - Metal conduit is out for domestic once you start involving many corners. #6 - MICC/MICS is a possibility, but expensive, needs tools, IR 1kV test-gear. #7 - Steel sufficient to prevent penetration by nail (conduit is 2mm CDS).
BS8436 is the replacement for #4-7 and frankly "about time" re domestic usage. Note it has I think a 12x bend radius so nothing like FTE which is much more co-operative. FP200 is not BS8436 re i) nail test ii) FP insulation when BS8436 specifies GP8 hence no FP200 can be both FP and GP8 iii) the foil on most BS8436 I've seen is more substantial than FP200 probably re nail test.
It is a pity that TLC QVS TradingDepot DiscountElectrical Screwfix do not carry BS8436 in cut-length, even if that means multiples of 25m (keeps it simple re 3 reels on the rollers and investment of =A3400-550).