I'm a dual citizen living outside the UK but I visit the UK regularly. My British passport is about to lapse. I hold another EEA passport.
I know that if I can't show a valid British passport I'll have to pay for an ETA now. But that's only 10 pounds for 2 years whereas a whole new passport, applying from overseas, is 120 pounds for 10 years.
I know you're supposed to enter the UK on a British passport if you have one, but am I required to have one or can I just essentially behave as though I'm not a British citizen for the purposes of travel? We only go for short visits to see family, I don't need to live or work there.