The UK is investing heavily in getting its science codes ready for the Exascale era. The ExCALIBUR project is a 5-year, £45M program focused on codes and algorithms, getting them ready for Exascale architectures. A key issue for ExCALIBUR is what parallel programming models to adopt, and so in this talk, we will examine these drivers, and explore how parallel C++ models such as SYCL are being evaluated and adopted.