No, it won't do any damage, only problem is that it could be a bit dangerous if a fuel line should start leaking or if you are involved in an accident.
It would be better to bring some temporary wiring inside the car so you can cut it off faster - you certainly don't want to be working under the bonnet while the engine's on fire!
'08 Chrysler 300CRD (MB OM 642 engine)
'95 E220 estate
'89 230TE (R.I.P.)