MIAMI (Reuters) - Republican presidential candidate Michele Bachmann's campaign said on Monday she was only joking when she described Hurricane Irene and last week's earthquake in the eastern United States as a warning from God.

The Minnesota congresswoman, who has gained media prominence for her fiery attacks on Democratic President Barack Obama, said in Florida that Irene was an act of God to get politicians' attention to the debt and deficit problem.

"Of course she was saying it in jest," Alice Stewart, spokeswoman for Bachmann's campaign, told Reuters.

Irene killed at least 21 people and cut power to 5 million homes and businesses along its path up the eastern seaboard from North Carolina. Vermont was battling the state's worst flooding since 1927 after Irene swept through as a tropical storm late on Sunday.

A rare earthquake also rocked the East Coast last week.

"I don't know how much God has to do to get the attention of the politicians. We've had an earthquake; we've had a hurricane. He said, 'Are you going to start listening to me here?'" Bachmann said at a campaign event in Sarasota, Florida on Sunday.

"Listen to the American people because the American people are roaring right now. They know government is on a morbid obesity diet and we've got to rein in the spending," she said.

Bachmann, among the top three candidates to win the Republican nomination and take on Obama next year, made similar comments elsewhere in Florida on Saturday, drawing some laughs from her audience.

Bachmann is a favorite of the fiscally conservative Tea Party movement and of religious social conservatives, but recent Republican presidential contender polls have shown her lagging behind Texas Governor Rick Perry and moderate Mitt Romney, who appeals to the party's business wing.

Bachmann has made a series of gaffes on the campaign trail, including mixing up Elvis' birthday with the anniversary of his death in a speech. During the 2008 election campaign she said Obama may hold "anti-American views" but later stepped back from the statement.

(Reporting by Pascal Fletcher in Miami and Todd Melby in Minneapolis; Editing by Jackie Frank)