There is a basic rule in CTA 2009 303 (4) that
" A debt does not arise from a transaction for the lending of money for the purposes of this Part so far as it arises from rights conferred by shares in a company."
But there is anti avoidance legislation in CTA 2009 section 521 to apply loan relationship rules to certain shares accounted for as liabilities. But in turn CTA 2009 521 D carves out certain excepted shares that aren't caught by the anti avoidance provision. This includes a "qualifying publicly-issued share."
So in general preference shares held as investments should be outside of the loan relationship legislation.
