Thanks for your reply.

At this stage it's been unconfirmed for 23 hours and counting whereas previous transfers (of lesser amounts) were confirmed within 1-2 hours max. The fee is the default fee set by BTCMarkets which they say is a 'fee charged that get's it processed with the highest priority'. Do you know what could be holding this up if my fee is high enough?

Just want this sorted asap as some of the alts I've been watching are at a good buy in price and it's just a matter of time before I think they will rebound.