Kemi Badenoch will say the Conservatives must do more than criticise Labour in order to win the next general election, as she launches her campaign to lead the party. Potential dividing lines with her leadership rivals already appear to be forming, after Robert Jenrick said on Sunday he would oppose Labour’s “declaration of war on the middle classes”. Badenoch will say the party should move on after losing the election in a landslide to Keir Starmer’s party in July. She is one of six MPs who have put themselves forward to become the Tory party’s next leader. In recent days Tom Tugendhat, Priti Patel and Jenrick have all given speeches, marking the start of the leadership election in earnest. James Cleverly will also give a speech on Monday, and Mel Stride has declared his candidacy. At a campaign event, Badenoch is expected to say: “If the Conservatives want to become worthy of the British people’s trust again, we can’t just sit around pointing out how terrible Labour are … fun as it is. “We can’t just keep having the same policy arguments from the last parliament. We lost. We are not in power. Labour will fail; and when that time comes, and the British people are looking for change, we have to be that change.” Badenoch, who was business secretary in Rishi Sunak’s government, has since become the shadow secretary for housing, communities and local government. She will say the Conservatives must think afresh about the future of the party and of the country. She will say Labour is “clueless, irresponsible and dishonest” and that it is trying to deceive the public over government finances. “The British people are yearning for something better and this Labour government is not it.” Cleverly, the shadow home secretary, will call for the party to be “honest and realistic” about the size and role of the state under a Conservative government. “The state should focus on doing fewer things very well, not everything badly,” he is expected to say. On Sunday, Jenrick said the party should “fight against [Keir Starmer] crushing wealth creators and working people”. He said the October budget would amount to a “declaration of war on the middle classes”. Conservative MPs will vote in ballots this week that will result in two candidates being dropped from the race. The final result of the leadership contest is due to be announced on 2 November.