Complex sentence: A barrister is in principle required to act for any client offering a proper fee, regardless of the attractions or disadvantages of a case, if he is available to take the case and feels competent to handle the work.
Split into simpler sentences: A barrister is in principle required to act for any client offering a proper fee, regardless of the attractions or disadvantages of a case. However, there are some modifying conditions, namely, that the barrister is available to take the case and feels competent to handle the work.