I would refer the committee's attention to page 71 of House of Commons Procedure and Practice. Related to the point that you've just raised, it reads the following, under the heading “Freedom of Speech”:
By far, the most important right accorded to members of the House is the exercise of freedom of speech in parliamentary proceedings. It has been described as:
“…a fundamental right without which they would be hampered in the performance of their duties. It permits them to speak in the House without inhibition, to refer to any matter or express any opinion as they see fit, to say what they feel needs to be said in the furtherance of the national interest and the aspirations of their constituents”.
Much has been written about this over the centuries—