And oddly enough a reply from the DoT today accepting a mistake was made in the LASORS but telling me TOUGH.
Copied below - only took them 5 weeks to reply.
Pilot Licensing
Thank you for your enquiry of 14 July about the requirements for maintaining instrument ratings.
I am sorry to hear about the difficulty that you are facing in maintaining an instrument rating. Unfortunately the amendment of LASORS in December 2010 was made to correct an error in the guidance and did not reflect a change of policy. The UK Air Navigation Order does not allow credit against the requirement to take the Instrument Rating (IR) exams on the basis of non-UK civil qualifications where the UK rating has lapsed for over seven years.
The UK adopted the European JAR-FCL requirements as its national standard for most pilot licences from the year 2000 onwards. At that time it was decided that, to reduce regulatory burden and complexity, the JAR-FCL requirements for revalidations, renewals and the addition of ratings would also be applied to the equivalent UK non-JAR licences. This was formalised through an amendment of the Air Navigation Order introduced the requirements for the renewal an IR on a UK licence. Therefore the requirement to retake the IR theoretical knowledge examinations has been a legal requirement since the year 2000.
I understand that the error in LASORS arose because other related JAR-FCL requirements gave National Aviation Authorities greater scope for flexibility where the expiry period was less than 7 years, and the CAA decided to give UK licence holders credit for IRs they held on licences issued in other countries. These credit arrangements were set out in the CAA’s advisory publication LASORS. However, the text of LASORS stated that the requirement to retake the lR(A) theoretical knowledge examinations for IRs that had lapsed by more than 7 years would not apply to pilots with UK military or other civilian IRs that had not lapsed by more than 7 years. Unfortunately, this was incorrect and contrary to the Air Navigation Order. When this was discovered during a review in 2010, the CAA amended LASORS to correct the wording to align with UK law.
As you may be aware, new EU flight crew licensing requirements, know as Part-FCL, have recently been adopted. Part-FCL also requires the retaking of the theoretical knowledge examinations where instrument ratings have lapsed by more than 7 years. Part-FCL is contained in directly applicable EU legislation and all EU licence holders will have to comply with its requirements.
I hope that this explains the situation.
Yours sincerely,
Duncan Nicholls