In a clear signal that the White House is preparing to turn its attention from healthcare reform to climate change legislation, one of president Obama's top advisors launched an impassioned call for the US to embrace low-carbon policies last week.

Speaking at a Washington energy conference, Larry Summers, head of the White House's National Economic Council, warned the long-term economic health of the US would be jeopardised if it failed to pass ambitious climate change legislation.

Describing it as "imperative" for the US to tackle climate change and " address the consequences of excessive dependence on oil for our national security", Summers underlined the importance of the administration's plan to pass climate change legislation.

"If you think about the risks to our ecology, the risks to our security, we minimise those risks with comprehensive energy policy," he said. "And if you think about the opportunity to lead in what is really important, we maximise that opportunity with comprehensive energy legislation. That's why energy is so crucial a part of president Obama's economic strategy."

Capitol Hill insiders said Summers' speech suggested president Obama was gearing up to try to pass the draft climate change bill being prepared by Democrat senator John Kerry, Republican senator Lindsey Graham and independent senator Joe Lieberman ahead of November's mid-term elections.

The Democrat leadership has consistently said it would try to pass the bill this year, but a number of Democrat senators had warned that they would prefer to see a vote delayed until next year after the battle to pass healthcare legislation proved so divisive.

Dan Weiss, a senior fellow at the Center for American Progress think-tank, told the New York Times that the president was likely to intervene directly to help secure the 60 votes necessary to pass the legislation.

The president met recently with a group of senators who are expected to hold crucial swing votes and Weiss predicted further meetings could be on the cards as the administration rushes to pass the bill ahead of mid-term elections during which the Democrat's Congressional majority is expected to come under fire.

"There's something about the president or vice president of the United States talking to you about these things that helps get to 'yes,'" he said.

Meanwhile, green businesses are also preparing for what promises to be a brutal fight with Republican senators and climate-sceptic lobby groups over climate change legislation with the launch of a new advertising campaign in support of the proposed climate bill.

The campaign is backed by more than 3,000 businesses, including the American Businesses for Clean Energy and the US Climate Action Partnership, and has secured support from a number of America's leading brands, including Google, Nike and Timberland.

The print ad, titled "A Question of American Leadership", urges Congress to enact bipartisan climate and energy legislation that "increases our security and limits emissions, as it preserves and creates jobs".