Deep hole

[nachoman]

Sometimes if I only need a tool for one specific job, I head on down to harbor freight ("garbage freight"). I know they carry long drill bits for much less than what you would get at the hardware store. They may not be professional quality, but they are much cheaper and will get you through a job or two. But since you are in the UK, I don't know if you have a similar supplier of cheap "made in china" tools.