This may help, it would seam you can be pursued up to 20 years for the debt and that time starts each time the bank contacts you,
This may well be the reason that no one knows of anyone going back to the UK after handing back there keys being pursued for the money, they will do the same as the UK i guess and give it plenty of time for you to get some money together
That article implies that handing back your keys in the UK and US is easy, not so in the UK – they can peruse you for the debt for many years. And only certain states in the USA allow jingle mail, not all.
Going bankrupt in the UK will also debar you from many forms of employment and probably prevent you getting credit in future.