Thanks. Advice on here plus google searching has helped me to resolve the issue (for now at least).
as per your comment, I had to remove glove box and undercover to access the blower motor. I gave the motor a few manual twists and applied some wd40 into the moving bits and it is now working fine again. I understand the car had been static for about a month, so that may have caused the sticking motor issue. Anyway, now working.
the only impact was that when I put everything back together again and started car, I got an airbag fault which would not disappear. Again, google and this site indicated that this was caused by disconnecting electrical connections when removing glove box and then turning keys to test the blower whilst the glovebox was removed (which I obviously would do), not realising the knock on warning light effect.
Anyway, local mechanic cleared the fault and all is now good.
i wonder if the way to prevent this happening if I need to access the motor again is to turn off the passenger airbag first before disconnections any connections?
PS. £60 for new motor sounds like a bargain. Do you have a link?