In a dramatic sign of how he has buried the era of his Rose Garden appearance with David Cameron, the deputy prime minister criticised the Tories over a "vituperative, vitriolic and highly personalised" campaign in last year's AV referendum.
Clegg used a Guardian interview to declare that the time had arrived to stop apologising for the Lib Dem presence in government as he challenged the Tories over civil liberties on two fronts.
In a letter to his colleagues on the National Security Council, the deputy prime minister said he could not accept plans to create secret courts in their present form.
Clegg has also been involved in a furious row with Theresa May over government proposals to give the security services new access to individuals' internet communications. He told the Guardian he would like civil liberties groups to challenge the plans when they are published as draft clauses for a new parliamentary bill, after the Lib Dem MP Julian Huppert threatened a rebellion.
"I will defer to Julian, as readily as I will to [the Liberty director] Shami Chakrabarti, when it comes to being a guardian on the high principle of liberty and liberalism," he told the Guardian. "It is actually something I genuinely care about a lot."
Clegg spoke out on civil liberties shortly after launching the Lib Dem campaign for the local elections in May. He said the elections would be difficult for the party because the same seats were last contested in 2008, two years before it took the controversial decision to enter government with the Tories.
"We now have to answer for the responsibilities in government in a way that we didn't have to four years ago," he said. "That is why I think we need to be even more forceful and remorseless in explaining our side of the story and setting out how we are seeking to deliver for voters and millions of ordinary people."
Clegg said the elections were taking place at a fortuitous time for the Lib Dems as he reeled off a series of recent achievements:
• A £1.25bn increase in the pupil premium.
• The Youth Contract, which will help half a million young people "earn or learn".
• The latest increase in the personal tax allowance which will benefit more than 20m basic rate taxpayers to the tune of £130 each.
• The biggest single increase in the basic state pension, championed by Steve Webb, the Lib Dem pensions minister.
• The biggest expansion in apprenticeships since the second world war.
Clegg expressed frustration with the slow pace of government delivery but, to the likely irritation of some Tories, he said he was proud of the achievements, some of which featured on the front page of his manifesto in 2010.
"Most of those were on the front page of our manifesto. But it takes a while just to get them going and to crank up the machinery of government to deliver them," he said. "I am much more forceful this year in saying this is the stuff we said we were going to do.
"I want us to get out and stop apologising for being in government, stop apologising for the difficult things we are having to do to pull the economy back from the brink. Instead we should highlight to people what we are actually delivering."
The deputy prime minister also contrasted the way in which Lib Dems govern with the Tories' approach. "Over the last couple of years there are some things we have proceeded with in sort a blunderbuss fashion, legislatively. But there are other areas which I am directly responsive for – on individual voter registration – where we have been very careful to publish stuff, scrutinise, react and amend."
The local elections on 3 May take place in a more harmonious atmosphere than last year's elections, which were overshadowed by the AV referendum. The leadership decided to adopt a more transactional relationship with their coalition partners after David Cameron asked Tory donors to fund the "no" campaign. The campaign accused Clegg of breaking his promises when he entered the coalition and eventually won out.
The deputy prime minister showed he has not forgotten the events of last year. "This time last year you had the very vituperative, vitriolic and highly personalised attack of the AV referendum which obviously we don't have this year," he said.
Clegg appeared more relaxed and more stoical as he launched the Lib Dem campaign in Stockport, where the council is run by the party as a minority administration. He appeared resigned to the fact that many on the left will not forgive the Lib Dems for entering into government with the Tories.
He said: "My own view is that people who dislike the Liberal Democrats because we are in coalition – we are not going to win them over over the next four weeks. But we are hopefully going to get through to people on the doorsteps that we are doing concrete things that will make a concrete difference to them. We just have to be very disciplined in drawing their attention to that."
He said that events in Europe over the past year had increased the pressure on the left. "You had the visceral backlash of trade unions and the Labour party to the fact of coalition itself," he said. "Since then, even amongst our staunchest critics, the events in Europe have just underlined over the last year that there isn't an easy option in Europe at the moment.
"There is not a magic wand solution where you don't need to make savings and all the difficulties can be forgotten about. That never-never land just doesn't exist. In a strange kind of way there is a more gritty realism about the invidious choices that all governments face in the over-indebted developed world now than there was a year ago."
