Contributing to 401k/IRA and UK taxes

Hi, just wondering whether anyone has been contributing to their US IRA/401k while living and working in the UK? And if so, does it help in terms of UK taxes? Thanks!

I think you can only put money into an ISA if  you pass a minimum threshold of US earned income. Interest income doesnt count. So if you are paid in £ in the UK, that does not count as US earned income, and will restrict your ability to put money into an IRA.

I would have thought putting money into a private IRA (i.e. not one associated with one's job) is irrelevant of income?  So if I win the lottery today, quit working for life, wouldn't I still be able to put the $5,000/year into my Roth IRA?  (Assuming, of course, that I still qualify income-wise to utilize a Roth IRA.)