In such a situation, you will not be allowed to leave the country in the first place. If your passport is about to expire and you need to travel urgently, go for the Fast Track Service and apply for a passport renewal immediately.
- What is an emergency travel document?
- What if my passport expires while I am abroad? Will I be permitted back into the UK?
- Can someone else take the relevant documents to the passport office on my behalf?
- I need a passport urgently. Is it possible to get it within a week?
- What to do in case of a stolen/lost passport?