EASA PPL application
It would seem best to apply for a Spanish PPL. If the Spanish will accept the Mayflower level 5 endorsement all the better, if not have the Spanish licence issued without it. You will not be able to use the Spanish licence outside of Spain without a minimum of English Proficiency level 4 endorsed.
If necessary transfer your Spanish EASA PPL and medical to the UK and use the approved Mayflower endorsement to include your level 5 in the UK licence. You may be required to undertake the UK FRTOL skill test to have the RT privileges included within your UK issued EASA licence.
Living in the UK, at any time after all this any UK RT or Flight examiner, in the future, can assess you as level 6.
Best wishes
Last edited by Fl1ingfrog; 2nd Feb 2018 at 21:28.