B&Q sell or sold performance power tools so either contact head office or your nearest store get them to order one quoting the machine type serial and model numbers. If you can't get one DO NOT USE and ordinary on/off switch it would be dangerous.
The switches on most tools are 'magnetic' no load switches I'm told the switch will not engage until power goes to the switch and operates the magnetic connection, a safety factor to prevent accidental switching on.
bob
October 2011
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix d.i.y tools.