The two figureheads of the country's first coalition Government since the Second World War spoke for the first time as "colleagues, not rivals".
"We are announcing a new politics," Cameron said, "a politics where the national interest is more important than the party interest. This is a remarkable and very welcome day."
Cameron and Clegg, who stressed they still represent "different parties", spoke repeatedly of the importance of forming a government that would be "stable" for Britain.
"This is so much better than the alternative," Cameron added, saying the two parties had been "inspired" in the last 48 hours to reach an agreement on a number of policies on which the two, until very recently, had clashed.
Cameron confirmed there would be a referendum on the alternative vote (AV) election system in the UK. "We felt it was right, given the [election] result, to make the concession," he said.
Nick Clegg said: "Until today we were rivals, now we are colleagues. This is a Government that will last. It will last despite our differences because we are united by a common purpose."
Cameron, who notably described the union as a "Liberal Democrat and Conservative" coalition, was asked about the dynamics of Prime Minister's Questions and public appearances.
"Is this a permanent joint leadership?" one journalist asked. "If the phone rings at 3am, will you both pick it up?" queried another.
"[PM's Questions] will be quite a different beast," Cameron said. "I will take the questions but Nick will stand in when I am away."
The coalition teams have published a document outlining "agreements reached" between the parties following the into-the-night negotiations of recent days.
It briefly outlines thinking on the deficit reduction, tax measures, banking and political reform, among others.
Cameron said more detailed policies would be communicated in the coming days.
Categories: Better Business