Travelling to the UK at the end of July
For context, I have dual British and American citizenship and am currently living in Spain and have been for the past 9 years (I've actually never stepped foot in the UK). My US passport is valid, my British one isn't and has been sent (along with other documents) to get a renewal. Me and my friends have been planning a trip to London from the 22nd to the 28th and the documents have *just* arrived to the UK, making me worry that it won't arrive on time for my trip. My question is, how viable would it be for me to get an ETA with my American passport despite being a UK citizen. Would there be some kind of penalty, would they somehow figure out, etc? I've been considering getting an emergency travel document but it appears to be only one way and I'm not entirely willing to cash out 125 pounds. I'm completely aware it all has been abysmal planning on my part but I just wanna see if there might be a viable solution.