Monbretia: it says that "when the fixed rate period as selected by me/us ends, the mortgage will transfer to a standard variable rate mortgage (not linked to the ECB) unless I/we request a new fixed rate or transfer the mortgage to the prevailing tracker rate at the time of transfer" - so, fair enough I may not automatically transfer back to a tracker, but, in my opinion, I should have had that as an option? That is what I specifically queried and requested at the time of fixing.
There are serveral other paragraphs, not least that "I/we consent to the variation of the terms of the Loan Offer....in particular the application of the Terms and Conditions of the Standard Morgage Product to the Loan Account"
The T&Cs of the original tracker product actually do not permit Fixed Rate periods, so from a legal point of view I can see why there was a need to vary the Loan offer.
However, like you said, it seems the intent of the form/letter has been adapted to suit another purpose
Peteb: thank you, I have seen your excellent post on your dealings with UB...however, I think this FA form/letter is the particular sticking issue