My local hardware store stocks it Dougie – but it's very unlikely you live anywhere near Wokingham.
However, I do try to buy stuff there whenever possible, simply becuase he stocks stuff I can't normally get at the DIY stores (JB Weld, Gorilla Glue etc). It might be strange to say this – but in some ways he has a much wider/better range of stuff than they do (maybe I mean its a bit more specilaist?) and is also pretty knowledable about it too. He clearly talks to his other customers about what works best for them.
It may be a bit more expensive, but I feel it's worth my while to try and help him stay in business. My purchases are generally small in nature and his prices not so bad and sometimes (to my surprise) he's cheaper than our local Homebase.
Of course you can probably also get anything you want mail order on the InterWebby these days – but then when you want something to finish that urgent plumbing job for your Manager – that might not be quite as handy.
So give your local hardware shop a call Dougie! 
Regards,
IanT