Investigating a terror suspect often requires gathering evidence from foreign countries.
Computer files have to be opened that have been encrypted by the most advanced methods.
Mobile phone records have to be studied, again from more than one country.
Thousands of hours of CCTV have to be scrutinised.
After 7/7 one address took 14 days to make safe enough to search.

These are the reasons given by the police for needing extra time.

I trust them more than a bunch of politicians desperate to topple Blair and get their own snouts deeper in the trough.

(How unusual for Akeneaton and friends to be alligned with the Tory party on this issue!)