Complex sentence: Mann appeared as a witness at the 2013 Ronnie Fraser vs. UCU employment tribunal hearing, in which Fraser accused the University lecturers union, the UCU, of antisemitism, the by then former Labour MP Denis McShane and John Mann testified on Fraser's behalf.
Split into simpler sentences: Mann appeared as a witness at the 2013 Ronnie Fraser vs. UCU employment tribunal hearing, in which Fraser accused the University and College Union, the union representing lecturers, of antisemitism. The by then former Labour MP Denis McShane and John Mann testified on Fraser's behalf.