A private speech in which US presidential candidate Mitt Romney ridiculed supporters of rival Barack Obama has been captured on film and broadcast on the internet.

The speech, which was recorded using a hidden camera, has been published by liberal political magazine Mother Jones and could become a key weapon for Obama in the forthcoming presidential election.

In the speech, which was delivered to a small group of Republican donors, Romney said that nearly half of the American electorate will vote for Obama in the forthcoming election regardless of his policies, because they harbour a victim mentality and avoid paying tax.

The candidate told his audience that "there are 47 percent of the people who will vote for the president no matter what. There are 47 percent who are with him, who are dependent upon government, who believe that they are victims, who believe that government has a responsibility to care for them, who believe that they are entitled to health care, to food, to housing, to you name it.

"These people [who vote for Obama] pay no income tax. My job is not to worry about those people. I'll never convince them they should take personal responsibility and care for their lives."

It is believed that the speech was filmed by a private donor who was present at the meeting. The faces of the participants were blurred except that of Romney.

Damaging

Analysts believe Romney's remarks could be hugely damaging for his chances in November's presidential election, as he is already widely characterised as a wealthy, out-of-touch businessman.

In response to the secret video, Obama's campaign manager Jim Messina said: "It's hard to serve as president for all Americans when you've disdainfully written off half the nation." Unconfirmed reports also suggest the video may be used for Obama's television campaigns in the coming days.

Romney was quick to engage in damage control following release of the footage. He said his remarks were not elegantly stated and they were off the cuff. But he stressed that he stood by every statement in the video.

"I'm sure I could state it more clearly and in a more effective way than I did in a setting like that," Romney said during a hastily arranged press conference.

Mitt Romney
Mitt Romney has risked further controversy by deriding President Obama's voters - Reuters Reuters