Don’t risk it – as I say as a U.S. citizen who has to go to the Embassy to get an emergency passport, at a cost of $165, because HMPO is so delayed. Doing this means that the passport HMPO has is now cancelled, and I’ll then have to exchange this limited validity one for a full validity one once my US travel is finished.
Even if you get the British passport, as I did, you can’t use it to enter the US. I’ve been waiting five weeks since my British passport was printed for the return of documents. I have called multiple times and was told it “should” arrive within two weeks, then three, then four…. Still waiting!
The last person I talked to said that HMPO is prioritising mailing out passports, so the supporting documents are basically sitting there indefinitely. Absolute shambles.