Autobrakes,
How would you continue then if you don't have the legally required approach charts for the airport you are intending to use!!
I have been in an airline before who left the Jepp pack on the aerobridge and this was realised about 3 hours into a 5 hour flight. After talking to the company and relevant authorities they turned around and came back to the origin airport as they couldn't get permission to carry on without the LEGAL paperwork.
If they carried on to LHR and just happened to be ramp checked by the CAA they would be in serious trouble if not charts were onboard for the destination.