The Serious Organised Crime and Police Act 2005 was rushed through, "on the nod", with minimal debate, during the undemocratic "wash up" process at the end of the last Parliament when the General Election had been called.
The bulk of the Act deals with the setting up of the Serious Organised Crime Agency, but there are also sections such as:
Section 110 Powers of Arrest
From 1st January 2006 this section makes any offence, no matter how minor, into an arrestable offence. Arrests by the police these days can mean taking 10 fingerprints and two palm prints, a DNA tissue sample and processing it into a digital "DNA fingerprint", forcing you to remove any facial coverings, (even those worn for religous purposes) to take photographs of your face etc. All of these items of personal data can then be retained forever, even if you are not charged, or any charges against you are dropped, or if you go to court and are found not guilty.
These new powers are regulated by the new statutory Police and Criminal Evidence Act 1984 (PACE) Code of Practice G (.pdf)
Section 128 Trespass on a Designated Site - e.g. Crown Property or National Security
Sections 132 to 138 Demonstrations in the vicinity of Parliament - the controversial restrictions in detail.
The Public Whip website has details of how the Members of the House of Commons voted on these controversial clauses.