Children’s care worker Celestina Mba, 58, will say that an employer has a duty to “reasonably accommodate” the beliefs of a Christian worker.
Ms Mba brought the original claim after her employer, which offers 24-hour care for disabled children, would not promise her that she would never be put on shift on a Sunday.
The Baptist and mother of three told The Sunday Times she had faced criticism for her stance but argued she was not trying to impose her beliefs on anyone else.