Talkinpeece
As I keep saying the person needs to renew their British passport from the U.S. I have been renewing my passport from the U.S. since the early 1970's. The UK border people do not ever ask what a British citizen has been doing out of the country.
I believe you have to be back in the U.K. for 6 months before you can use the NHS ands that would be probably the same for voting again.
If you have a US passport you will have neither ESTA nor Green Card
Absolutely untrue. You certainly DO NOT not need a green card if you have a U.S passport. You cannot be a naturalized U.S citizen and a green card holder. You hand over your green card when you become a citizen.
If you have a UK passport it will have the full issue details and your US immigration status on issue linked to the electronic record that UKBA see on their screens
I am born and raised British and have a British passport and it does NOT have any information anywhere on it about my U.S immigration status. In fact when I was boarding a plane at Heathrow to return here once the person checking passports at the gate mentioned mine was about to expire in a few months. He have no idea I was a U.S. resident and going home by looking at my passport.
I do not know how often you fly in and out of the UK on your Blue passport but I can promise you that UKBA are an absolute PITA if there are any anomalies in the records
My passport is a dark red not blue. I need to make it clear to you that there are no anomalies on my passport or anywhere else. I believe in following the law. I'm a legal U.S resident and would never dream of breaking the laws in the U.S or the U.K. I find it easier to be law abiding.
Buying a one way ticket out of the USA with a shiny new British Passport will ring alarm bells with the Airline, with UKBA and with DHS.
I have flown out of the U.S. using a newly issued British passport and there was no problem. You are allowed to travel with a new passport and people have to get a new one for many reasons.
You obviously have an issue with Trump and I think that might be because he wants immigration laws followed - as Obama did as well.
The op's family member might not have become a legal U.S resident because she couldn't for some reason. Maybe she had a criminal record, or maybe mental health issues - or drug resistant TB - who knows. To become a U.S resident you have to be well vetted. Criminal background check, medical examine etc.
As I said before I have been living away from the U.K for many years and still have my NI number (somewhere) and my BC. I can return home anytime if I wanted to, even with a brand new passport.
I was referring to appointments within the US
Showing up for an immigration appointment within the U.S. after you've been living her illegally for 15 years would get you arrested - and rightfully so. The person needs to leave the U.S before she is deported and she will be sooner or later, and then she needs to make an attempt to reenter legally.