It depends on what sort of engine you have. If you have the old style low pressure indirect injection type, usually has a mechanical pump driven by the cambelt, no seperate in-tank pump, and mechanical injectors, then you'll be alright as they'll run on anything-the petrol will just act as an injector cleaner.
If you have the modern type high pressure direct injection engine- usually identified by electronically controlled injectors, lots of other electronic gizmos and plastic covers under the bonnet and HDi or similar on the boot, then do NOT drive it, get the fuel system cleaned out- it'll cost but not as much as having the system replaced will.....modern diesels do not take kindly to even a small amount of petrol in the system and with high pressure pump systems costing usually over a grand to replace you really don't want to take the chance!
Unless of course you are going to get rid of it in the next 6 months or so........