David you are entitled to use the NHS as long as you decide to
resume your residency in the UK after having lived abroad.
(from the NHS website)
Are you taking up or resuming permanent residence in the UK?
Under the current Regulations, anyone who is taking up or resuming permanent residence in the UK is entitled to
free National Health Service (NHS) hospital treatment in England.
If your intention is to live permanently in the UK you will be exempt from hospital charges from the date of your arrival in the country but you should expect to be asked to prove your intention and that you are legally entitled to live here. This exemption applies to your spouse, civil partner and children (under the age of 16, or 19 if in further education) if they are living here with you on a permanent basis.
http://www.dh.gov.uk/en/Healthcare/E...able/DH_074376