UK passport, burgundy cover, near Central Station

I lost my UK passport yesterday around 3pm. It's a burgundy biometric passport with the gold crest on the cover, plus a small crease on the bottom-right corner and a faint pencil mark 'A12' on the inside back page. I think I had it near Eldon Square outside the Central Station entrance on Northumberland Street in Newcastle. I’m due to travel in two weeks for work, so I’m really worried and would be grateful to get it back. It means a lot to me because it’s travelled with me on many trips.