Thank you all for your advice. I took it back to Homebase this morning.
They insisted on checking it themselves, tried plugging it in and
loosening chuck as suggested by Rob and it still didn't work. Got their
mate to come over and look at it as well. Ten minutes later they
conceded that it was faulty and decided to replace it. They then got
shirty when I insisted on unwrapping the replacement and checking that
it works which it does so I now have no more excuses left.

brenton