Just land up at Durham Passport office as early as possible today (Saturday). I think they work from 8 – 1530 on saturdays. Go with a copy of your ticket. From my understanding, if you are more than 6 weeks after submission, they will consider upgrade – for more than 10 weeks it is a free upgrade and for others it is a paid upgrade. If everything else is ok, you will get your passport in 3-4 hours. Go to the office where it is being processed. That way, they can get things done locally quicker.