ChasG - see
http://www.nationalprivatepilotslice...20REV%2009.pdf section 4.4 on pages 22/23:
4.4 Incomplete training on other classes of aircraft
Credit towards the grant of an NPPL with Microlight Class Rating may be given for flight training on other classes of aircraft. A maximum of 10 hrs credit will be given for any such training conducted with an authorised UK flight instructor; applicants seeking credit for other flight training should contact the BMAA for advice.
Applicants for a Microlight Class Rating without Operational Limitations shall pass the Microlight theoretical knowledge examinations, including the Microlight Aeroplanes Type (Part 2) oral examination conducted by a Microlight flight examiner and complete not less than 25 hours total flight training, to include the following flight training on Microlight aircraft:
(1) Not less than 5 hours of navigation training with an authorised Microlight instructor in the 9 months before licence application;
(2) Not less than 10 hours solo under the supervision of an authorised Microlight instructor in the 9 months before licence application, to include:
(a) 3 hours navigation;
(b) 2 qualifying cross-country flights as defined in the NPPL Microlight Syllabus;
(3) Pass the NPPL GST.