The polarised gluon density $Delta;G(x) from di-jet events at high energy ep-colliders

We present the potential to determine the polarised gluon density from boson-gluon fusion processes with di-jet events at future high energy ep-colliders. These include HERA at DESY operated with polarised electrons and protons, polarised protons from HERA colliding on polarised electrons from a future linear collider, and polarised protons from RHIC at BNL colliding on electrons from a future electron accelerator.