There'll be an Emergency debate in the House of Commons today (6th July) on the current phone hacking scandal surrounding the 'News of the World', using the provisions of Standing Order 24.
Standing Orders are the rules made by both Houses of Parliament for the regulation of their proceedings. Standing Order 24 allows an MP to make an application for the House of Commons to:
"debate a specific and important matter that should have urgent consideration. If the Speaker is satisfied that the matter is proper to be so debated, the Member shall either obtain the leave of the House, or, if such leave be refused, the assent of not fewer than forty Members who shall thereupon rise in their places to support the motion, or, if fewer than forty Members and not fewer than ten shall thereupon rise in their places, the House shall, on a division, upon question put forthwith, determine whether such motion shall be made."