You can apply for addition of a Microlight Class Rating to a UK national PPL or NPPL in accordance with CAP 804, Section 5, Part A, Subpart 2, page 7, para 3.13 on the basis of a current SEP class rating with microlight differences training completed, as a paperwork process only. No red tape here
3.13 Issue of Microlight Aeroplane Class Rating on the basis of an SEP(Land) Class Rating
Provided that an SEP aeroplane class rating is valid in a UK national licence, an Examiner may revalidate the SEP aircraft class rating as a Microlight aircraft class rating. The Examiner makes the relevant entry in the Certificate of Revalidation page in the holder’s licence, entering the revalidation date in the “Date of Check or Test” column and entering the “Valid To” date as 24 months later. The holder must then apply to PL for the inclusion of the Microlight Class Rating in their licence as the Examiner is not permitted to make entries in the ratings page of the licence.
If the SEP rating or the licence has expired, application for an NPPL with the required ratings should be made to the BMAA (for Microlight) or the LAA for SSEA/SLMG.
Here's the form on the NPPL website
- see the final tick box in Section 1 of the form.
I think you will find it filed next to the safety case for the national licence holders not being allowed to fly EASA certified or EASA permit aircraft from April 8th 2018.
Now, there's a Red Tape Challenge!