Depends on the OP's UK bank, of course, but mine (Co-op) has never required me to activate replacement debit and credit cards which they send to my Thai address. Indeed, the 16-digit numbers remain the same, the only things changing are the 3-digit CVC on the back of the card plus, of course, the validity dates.
But even if this were also the case for @cliveshep, I would still strongly advise him to initiate a token payment with his replacement card in due course (perhaps in the form of a Wise transfer?) so as to ensure that any potential problems with using it for his passport renewal payment were identified (and, hopefully, resolved) beforehand.