PhilD,
Unless my reading of Schedule 11 of the ANO is incorrect...
If only things in life were so simple that reading one document gave you all the necessary info.
Sadly not. In this instance any request for additional ID may be legitimate under the 2001 Anti Terrorist rules. (cf the Newcastle SB rules, now relaxed)
Common sense will prevail, but it's far quicker to carry some photo-ID when you want to return airside!
Exeter give you a pass "out" which must be re-presented to get back airside - seems to work well enough.
big.al,
Hope the weather is better tomorrow than it is here currently