Terrorism Bill

May I press the Minister a little on the matter? I have some experience of visiting nuclear sites and I want to know at what point I could become a criminal. If a group of wholly innocent people were encamped outside AWE Aldermaston to protest about the development of a new generation of nuclear weapons and if, to protect themselves from rain and wind, they attached the edge of a tarpaulin to an outside perimeter fence, but had not crossed the fence, would they be committing a criminal act?