By politics.co.uk staff

As of today, extreme pornography becomes illegal to own in the UK.

To read a feature on the arguments against the new law click here.

To read a comment piece on the new law click here.

To read analysis of the law click here.

The change in the law followed the brutal murder of Jane Longhurst, whose killer, Graham Coutts, admitted being addicted to violent internet pornography.

At the time, her partner said: "Jane would still be here if it wasn't for the internet."

The government became convinced of the need for a change in the law after a concerted campaign by Ms Longhurst's mother, Liz, to have extreme pornography banned, including a petition of 50,000 people.

But privacy campaigners and libertarian groups have condemned the law as an infringement of personal freedom.

In a comment piece for politics.co.uk, Julian Petley, professor of Film and Television at Brunel University, said: "Appeasing the moral authoritarians has always been at the root of this measure".

The law bans pornographic images which depict an act which threatens a person's life or would cause serious harm to the anus, breast or genitals, regardless of whether the scenes are real or acted.

There are also bans on depictions of sex with animals or corpses, regardless of whether the animal or corpse is real.

There is considerable uncertainty over how many people will be prosecuted under the law, ahich is very broadly framed.

Over the weekend, the Ministry of Justice (MoJ) said it only expected to see a small number of prosecutions per year over the law, which carries a maximum sentence of three years.

A statement from the Association of Chief Police Officers (ACPO) said: "The police will not be actively targeting members of the public but will be conducting investigations into the unlawful possession of this material where found."

Katherine Rake, director of women's rights group the Fawcett Society, said: "It would make a nonsense of the legislation if there wasn't proactive policing around it."

The new law comes into force on the same day cannabis is upgraded to class B.