AndyH I am in the exact same boat as you. Also travelling on 1st Aug, also realised my child’s passport had run out in February, massive face palm moment.
I am a couple of days ahead of you though. I submitted my application and did all the necessary things on Friday 26th June. Sent old passport also to Durham by Track and trace. My progress is saying they have not received it yet but the royal mail tracking said it was signed for on Monday morning at 8am. Giving it 1 more day before I ring to find out where it is.
I will update with any progress so hopefully that helps.
