Ed Miliband has appealed to media covering the general election to concentrate on the "issues" at stake and not question the motives of politicians competing for power.
Speaking at a dinner for political journalists in Westminster, the Labour leader warned that public "cynicism" about MPs had a corrosive effect on the whole political system.
He said the parties were made up of people who entered politics for "right reasons" – regardless of their affiliation.
"You will shape this election too," he said in a direct appeal to journalists. "And my only request is that you do your bit too to try and make this election about the issues, choices and beliefs that matter to the country as well.
"One of the biggest enemies of politics is cynicism, the belief that we are all in it for base motives.
"Agree with us or disagree with us, but report us for what we believe. This is all we can ask for."
He added: "We may have different roles and be on different sides but as custodians of politics and its reputation, we are, as somebody else once said, all in this together."