Lib Dems paint themselves as party of civil liberties as leaders brace for snap election

Labour has been accused of building a "surveillance society behind the backs of the British people" as it has developed the world's largest DNA database and presided over an unprecedented growth in the use of closed-circuit television cameras.

The Liberal Democrats, who insist the issue of civil liberties is a key dividing line with the other parties, are demanding wide-reaching controls to protect personal privacy. Nick Clegg, their home affairs spokesman, yesterday published research which suggested levels of surveillance had been substantially extended in nine ways.

Mr Clegg said: "They have been building a surveillance society brick by brick behind the backs of the British people. When you put together the individual initiatives, a chilling picture emerges. It amounts to a radical redrawing of the rights of the individual against the powers of the state."

He said 4.2 million cameras now criss-crossed the country and a single individual could be photographed 300 times a day. The DNA database had more than 4 million entries – including samples from a million people without a criminal record – and could reach almost 4.5 million by 2010. He added nearly 10 million passports had been issued which had security chips vulnerable to hackers, criminal records checks were riddled with errors, and thousands of schools took fingerprints from pupils. Full-body security scanners that can "see" through clothes were being developed, mobile phone networks were being targeted by hackers, and more than 400,000 requests to bug telephones and computers were made in just over a year.

Mr Clegg's remarks came at the start of a crucial conference which the party leadership believes could be a springboard to an election that might be called within weeks.

Frontbenchers will meet this week to finalise the Liberal Democrats' manifesto and activists have been put on high alert for a snap poll.

Sir Menzies Campbell, the party's leader, told delegates yesterday that Labour had been "the most centralising, authoritarian and intrusive government in the post-war era". He denounced the Government for eroding the right to privacy, as well as freedom of speech and freedom from detention without charge.

"There has been no right too precious, too hard-won or too long-standing for New Labour not to want to trample on it," he said. The party also sought to carve out distinctive ground on tax policy by making clear it wanted taxes to rise for households earning more than £70,000 a year, which form the top tenth of earners.

Sir Menzies stressed that 90 per cent of the population would be better off under the plans, but asked by the BBC if that meant "hammering" the other 10 per cent, he replied: "Yes."

Vince Cable, the party's Treasury spokesman, will underline the emphasis on "fairer" taxes with a condemnation of Gordon Brown's "complacency" over soaring levels of personal debt. He said: "It's clear the Liberal Democrats' emphasis on fairer taxes – but not higher tax levels – with tax cuts for those on low and middle incomes, strikes a chord with the voters.

"There is genuine disgust at some of the tax dodging, including the abuse of non-domicile status, and a large majority share our wish to see a crackdown."

Today, party delegates in Brighton will vote on a far-reaching package of environmental measures to meet a pledge to make Britain carbon-neutral by 2050. Proposals include shifting all of Britain's power generation to zero-carbon sources by 2050, and banning petrol and diesel cars by 2040.