Taxation appeals commissioner should have designated a modified vehicle as a ‘motor caravan’

Appeal by way of case stated - decision of taxation appeals commissioner - whether revenue commissioners correct as a matter of law in refusing to classify a vehicle owned by the appellant as a 'motor caravan' - vehicle purchased in UK and brought to jurisdiction where modifications subsequently made - EU framework for approval of motor vehicles for taxation purposes - relevant provisions of EU law - definition given to 'special purpose vehicles' - domestic law requirements - establishment, by the revenue commissioners, of specific additional requirements for registration of converted vehicles previously registered in another jurisdiction - material part of decision of appeal commissioner - inability to use kitchen facilities from within vehicle central to determination of taxation class - vehicle not significantly altered from its previous state - vehicle not a 'motor caravan' - whether an error in law - principles to be applied - particular definition adopted by appeal commissioner of 'living accommodation space' - no evidence to support finding that vehicle is not designed to accommodate movement of persons within vehicle - older statutory definition of 'motor caravan' - previous broad discretion to determine motor caravan status - three approaches to interpretation of EU law - literal, schematic and teleological - principle of legal certainty mitigates against commissioner's determination of status - misapplication of EU law principles - natural and ordinary meaning of 'motor caravan' - determination of appeals commissioner reversed - appellant's vehicle is a 'motor caravan' within the definition of domestic taxation legislation