Labour is prepared for a “dirty and nasty” campaign ahead of next year’s general election, Sir Keir Starmer has said. The Labour leader claimed his project of reforming the party in the aftermath of the Corbyn era must go further and deeper than Tony Blair’s government. In a speech on Saturday, he said reforms were necessary because an incoming Labour government would have a bigger task than confronted Blair, owing to the severe challenges currently facing the country, on top of 13 years of Conservative rule. “If you think our job in 1997 was to rebuild a crumbling public realm, that in 1964 it was to modernise an economy overly dependent on the kindness of strangers, in 1945 to build a new Britain, in a volatile world, out of the trauma of collective sacrifice – in 2024, it will have to be all three,” he said. He highlighted Blair’s controversial move in 1995 to rewrite the Labour constitution, known as clause IV, ditching the party’s then commitment to mass nationalisation in a dramatic shift towards the centre ground. “This is about taking our party back to where we belong and where we should always have been … back doing what we were created to do,” Starmer told the Progressive Britain conference. “That’s why I say this project goes further and deeper than New Labour’s rewriting of clause IV … This is about rolling our sleeves up, changing our entire culture, our DNA. This is clause IV on steroids.” In a questions and answers session, Starmer acknowledged that the party faced a hard road ahead if it is to take power after the next general election. “I have always known it is going to get dirty and nasty. That is the nature of our politics,” he said in response to a question. “We can’t complain. It isn’t pleasant, but we have to get on with it.” But he said Labour should look forward to the challenge: “This is the bit where we get to talk about the future of the country, with hope.” Starmer’s comments are likely to alarm those on the party’s left who are already angered by his decision to drop pledges on tuition fees and the nationalisation of utilities. He has defended these shifts by saying his proposals have been adapted given unprecedented global events. He said in his speech that this zeal for reform is born from the fact that working people “no longer have faith in an unreformed state”. “We need to accept that nobody is going to unite behind the traditional Westminster way of doing things. Seriously, walk round any working-class community and you will be hit over the head by this,” he said, describing his plans as a “new partnership between politics and working people: a new Labour project for our times”. In this month’s local election, Labour gained 500 seats at the expense of the Conservatives, becoming the largest party in local government. However, there was a strong showing for the Liberal Democrats, too, fuelling speculation about a possible hung parliament and coalitions. In an interview, Shabana Mahmood, Labour’s election chief, insisted the party was on course for an absolute majority at the next election, based on last week’s local voting across England. She said there was “polite disagreement with some of the psephologists” who extrapolated the local election data to predict a hung parliament, given that last week’s voting did not take place in Scotland, Wales or London. Labour is particularly confident of making gains in Scotland. “So I think that when you look at the fuller picture, that’s why we believe we are on course,” Mahmood said. “But obviously there is a long way between now and actually completing that course. And that’s the next bit ahead for us. It’s not as if any of us are sitting there thinking this is in the bag. I’d be the first person to militantly stamp that out. It’s just we know it’s doable. We know there is a path there for us. And we’re very much on it.” Starmer’s speech comes at a point when Labour is under pressure to set out more big policies. Sources said more details of the party’s offering to the electorate would be set out in the coming months and at its conference in the autumn. Before then, the national policy forum process in July will begin to shape the priorities of a Labour government. In a briefing sent out to Labour members this week, 86 pages of proposals for debate at the forum included measures such as day one rights for workers, billions of pounds of green investment, reform of childcare, and a huge expansion of NHS staffing, as well as votes at 16. Starmer is yet to set out how his proposed reforms to the state would take shape, but he told the Observer last month that he would be “bolder” than the last Labour government on overhauling public services. He also set out plans to accelerate housebuilding and get more young people on the property ladder. In his speech, Starmer launched a new attack on the Conservatives for being “unconservative” and failing to understand people’s need for “stability, order, security”. “We must understand there are precious things – in our way of life, in our environment, in our communities – that it is our responsibility to protect and preserve and to pass on to future generations,” he said. “And if that sounds Conservative, then let me tell you: I don’t care. Somebody has got to stand up for the things that make this country great, and it isn’t going to be the Tories.” He said Rishi Sunak’s party did not stand up for “our rivers and seas, not our NHS or BBC, not our families, not our nation”. The Conservatives accused Starmer of a cynical rebrand, with the party chair, Greg Hands, saying: “Starmer has backtracked on every pledge he has ever made and he is now cynically trying to rebrand his own flip-flops as ‘reform’.”