WASHINGTON — Former President Bill Clinton is set to play a central part in the Democratic convention, aides said, and will formally place President Obama’s name into nomination by delivering a prime-time speech designed to present a forceful economic argument for why Mr. Obama deserves to win a second term.

The prominent role of Mr. Clinton, which is scheduled to be announced on Monday, signals an effort by the Obama campaign to pull out all the stops to rally Democrats when they gather for their party’s national convention in Charlotte, N.C. An even more important audience will be the voters across the country who will see the address carried by television networks.

“There isn’t anybody on the planet who has a greater perspective on not just the last four years, but the last two decades, than Bill Clinton,” David Axelrod, a top strategist to the Obama campaign, said in an interview on Sunday. “He can really articulate the choice that is before people.”

Vice President Joseph R. Biden Jr. will appear on the final night of the convention, making the case for Mr. Obama before the largest audience of the week during an outdoor speech at the Bank of America Stadium. The vice president and Mr. Obama will appear together on stage before they accept the party’s nomination for a second term in the White House.