Image caption David Blunkett says Labour got the balance between civil liberties and security right

Former Home Secretary David Blunkett has called for internet providers to block pornography, warning against a descent into "Sodom and Gomorrah".

Mr Blunkett backed an opt-in system of censorship, saying the Lib Dems had been wrong to reject it at their party conference last week.

Civilised society risked being undermined by "the most bestial activities", he warned.

He was speaking at a Demos fringe meeting at the Labour conference.

Lib Dem members voted last week to reject a plan for internet providers to block online pornography unless web users "opt in".

The vote put them at odds with their Conservative coalition partners who want UK service providers to impose "default" filters to block pornography. Labour has backed the Conservative position and urged the prime minister to go further and boost the resources of internet pornography watchdogs.

'Social order'

Mr Blunkett told the Demos fringe meeting: "The Lib Dems in Glasgow debated this and decided they were against automatic protection unless people chose to over-ride it, in terms of pornography on the internet and the protection of children. I think they were wrong.

The net today should not be like the forest in the 13th Century Helen Goodman, Shadow media reform minister Lib Dems reject porn filters plan

"I think we have a job in this country, in a civilised, free, open democracy, to protect ourselves from the most bestial activities and from dangers that would undermine a civilised nation."

Drawing a parallel with Germany before the rise of the Nazis, he suggested a loose moral climate had fed the paranoia and fear that had allowed Adolf Hitler to flourish.

"In the late 1920s and early 1930s, Berlin came as near as dammit to Sodom and Gomorrah. There was a disintegration of what you might call any kind of social order.

"People fed on that - they fed people's fears of it. They encouraged their paranoia. They developed hate about people who had differences, who were minorities.

"There always has had to be some balance, in terms of the freedom of what we want to do, for ourselves and the mutual respect and the duty we owe to each other in a collective society. I think getting it right is the strength of a democracy."

'Wild West'

Helen Goodman, Labour's shadow minister for media reform, reached further back into history to illustrate her point, comparing the internet to a lawless 13th Century forest.

"It would be quite wrong if we were to preserve a special place within the law, where the net could be outside the law. The net today should not be like the forest in the 13th Century.

"Robin Hood and the outlaws - they were called that because they were outside the law - that was not a sustainable position in the 13th Century and it's not a sustainable position now."

She said the same principles of law that apply in the real world should also apply online.

And she made the case for new laws making it easier for internet users to be traced through their IP address, something the government is investigating.

Nick Pickles, director of the Big Brother Watch pressure group, opted for another historical analogy, saying politicians exaggerated the extent to which the internet was a lawless "Wild West".

The real problem, he argued, was a lack of transparency and "privatised surveillance", with internet giants being paid to store data on citizens on behalf of the state.

Britain's outdated security laws were cloaked in secrecy and not publicly accountable - and had little or no judicial oversight, he added.

And he urged Labour to challenge "an outdated culture of surveillance and a legal framework that is struggling to keep up".

'Considerable threat'

Mr Blunkett, who was home secretary between 2002 and 2005, was in expansive mood at the Demos fringe, in front of an audience who felt the last Labour government had not done enough to protect civil liberties (there was a show of hands).

He said he was proud of much of what he had achieved as home secretary, such as the scrapping of the "double jeopardy" rule, allowing retrials of people cleared of serious crimes when new evidence comes to light, which had led to the trial of the Stephen Lawrence suspects.

But he admitted to early "hiccups" with the controversial Regulation of Investigatory Powers Act, which was initially abused by local authorities to spy on householders.

When asked why things had gone wrong, he said: "Because we are human and we are frail and when we pass something we can not guarantee that other people won't misuse it."

He also confessed to using overblown language in response to the terror threat.

"There were times when my rhetoric probably exceeded what was necessary.

"My excuse for this is that actually at a time of considerable threat, when people are fearful, the only way of securing their confidence and reducing their fear is to take sufficient, substantial but necessary action to make sure that they feel that someone is in charge and that they know what they doing and that they deal with those new international threats."

He added: "The idea that somehow the Labour government got it drastically wrong - I would say this wouldn't I? - is a nonsense."