How can I minimise the time to get a new UK passport?

Question

I am a UK citizen. I have lost my passport and planned to travel by Eurostar from London to Paris in five days' time. The quoted time for a fast-track replacement passport is "within 1 week" of an appointment.

1. When can I book the appointment? I.e., could I book one at 9am this morning, for midday? Could I book one for the evening (after 5pm) or would I have to wait until the next working day?

2. How likely is it that the new passport could arrive within less than a week? If I collect in person rather than it being posted, could I minimise the time to get one?

3. Is there any other way to minimise the time? E.g. if I have a scan of my old passport, and/or it was found by the police and returned to the passport office and cancelled? If I pay a premium?

Answer 1

My wife lost her British passport earlier this month. Here's the basic timeline...

3 July (Sunday): discovered the passport was lost
3 July (Sunday): filled out the lost passport form on the net
4 July (Monday): filed paperwork at the post office
6 July (Wednesday):  received call from the passport office to schedule an appointment
11 July (Monday): attended in-person interview at the passport office (Victoria)
16 July (Saturday): delivery service dropped off new passport at our residence

Despite not being eligible for the 'premium service' we basically paid for every upgrade available (we are headed off to Russia in a few days for a brief holiday). The total outlay was GBP 106. Plus photos. Plus travel to Victoria.

Based on this experience I have it in mind that the minimum time span to replace a lost passport from discovery to possession is 14 days for Brits who can make it to Victoria.

Note: "Victoria" = "HM Passport Office, London Victoria"