Part-time masters degree during TC

I am due to start the GDL in September and am currently looking to secure a training contract. Although I am dedicated to pursuing a career in law I am still very interested in history, which is what my undergraduate degree is in, and would like to study for a masters.

Would it be possible for me to study a part-time masters degree over the two years of a training contract? I am not looking to apply to magic circle firms I am looking at mid tier. Will I have time to do the necessary readings and writings over two years to complete the degree.

FYI, my TC is at a firm placed at the top end of mid size.