In her concession speech less than three weeks ago, Hillary Clinton urged supporters to transfer their loyalties to her rival: "Today I am standing with Barack Obama to say 'Yes we can'," she said. "We will make history together as we write the next chapter in America's story."

This evening, at Mrs Clinton's first joint meeting with Mr Obama since the campaign began, the former first lady will renew her call for the party to unify behind Mr Obama - a theme that will be echoed tomorrow when they appear for a rally in the town of Unity in New Hampshire.