Now 13 years of marriage and I just got this reply after I sent an email request for an update:
Only files that are currently approved by the Minister will be invited to
the upcoming ceremony in April.
Your application for naturalisation is currently being processed in the
normal way with a view to establishing whether you meet the statutory
conditions for the granting of naturalisation and will be submitted to the
Minister for decision when processing is complete.
Citizenship Team 8