Parliamentary Voting System and Constituencies Bill

My noble friend Lord Anderson was so quick on his feet that I did not have a chance to ask my noble friend a point that is directly related and relevant to the amendment that she has moved. I should like to ask her now, if I may. Noble Lords opposite know that I never give long speeches and I always try to speak to the point of a debate when I join it. I should like my noble friend to clarify how she arrives at the figure of 630. I genuinely do not understand why it is not, for example, 625 or 635. It would be very helpful to have the mathematics behind what she is proposing. I do not have a view about how big the House of Commons should be. I am inclined to believe that the number probably should be reduced but I do not understand how she has arrived at the figure that she is proposing.