Data Retention and Investigatory Powers Bill (Business of the House)

On the six-month period, I understand that Opposition Front Benchers have accepted the Government’s argument that the Bill will do no more than clarify the previous situation and will not extend the Government’s powers in any way. If we pass the legislation and subsequently have doubts about whether powers have been extended, will it be possible for the six-month review to look at the legislation, or are we stuck with it once we have it? What are Opposition Front Benchers trying to achieve?