As the general election starts in earnest, Mitt Romney is taking an aggressive tack.

The former Massachusetts governor told ABC News’ Diane Sawyer (with a chuckle) that his one message to President Obama would be, “Start packing.”

“I’d say, ‘Mr. President, focus on your policies,’ ” Romney added. “If he looks back honestly and looks at his policies, he’ll say, you know what, his policies have not helped the American people. They have not helped get jobs, they have not helped raise incomes and they’ve added trillions of dollars of debt.”

Ann Romney was interviewed with her husband; she said she would tell the president that “It’s Mitt’s time ... it’s our turn now.”

The interview airs tonight at 6:30 p.m.