Ascertained this is Natwests Fraud Team Automated Telephone number I rang it back and eventually connected to a human; was totally happy with the responses
Received a number of calls but refused to follow their automated service as I suspected it to be fraudulent. Rang Natwest card team via their main number when I got home - they confirmed the 0800 number above to be a genuine number. Better to be safe than sorry!
3 calls so far to day from this number purporting to be NATWEST bank having detected suspicious activity on a credit card. Automated voice askeing "press 1 or "call back on... Giving the same number.