With the storm of the mid-term elections in their rear-view mirror, a coalition of influential opinion-formers is preparing to launch a third political party in the United States next month that will eschew the partisan extremes of right and left and seek consensus in the moderate middle of American politics.

The unveiling in New York City on December 13 of the "No Label" Party will be seen widely as an almost inevitable response to the ever-deepening gulf between the conservative Tea Party movement on the one hand and determinedly liberal groups such as MoveOn.org backing President Barack Obama on the other.

It will also derive some credibility, its backers hope, from the outcome of the mid-terms, which saw moderates of both parties driven out of office in many parts of the country, leaving a US Congress that is arguably more polarised ideologically than ever before.

The driving forces of the new party are Mark McKinnon, a moderate Republican and former campaign adviser to Senator John McCain and President George W. Bush, and Nancy Jacobson, a Democratic fundraiser. Others giving their support include close advisers to Michael Bloomberg, the New York Mayor and independent, who has been invited to the inaugural event. It's not clear if he will attend. "There's nobody that gets rewarded for bipartisan behaviour," McKinnon said. "They get punished ... American voters are so hungry for more voice, and more choice."

But No Label backers will be gambling that the space for a third presidential candidate may be too inviting for Bloomberg to resist.

- Independent