In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

This clause is meant to allow the government to act quickly in case a major emergency comes up when Congress is not in session .
To allow the government to act quickly in case of a major domestic or international crisis arising when Congress is not in session , the president is empowered to call a special session of one or both houses of Congress .