On the 16th of February, the Government passed a law (in the Counter Terrorism Act) making it illegal to take a photograph of a police office, military personnel or member of the intelligence services - or a photograph which "may be of use for terrorism". The legislation is fairly vague which means that its going to be difficult to prevent the police from abusing it, just as they already abuse section 43 and 44 of the anti-terrorism act.
This act doesn't just affect the rights of photographers. By enabling police to threaten people with arrest for taking photos they will be less accountable in those rare situations when they cross the line. You can find out more from this article in the Guardian and when you are done reading, why don't you head over to Number 10 and sign the petition