With the battle over health care reform legislation nearing the final stages, a powerful business coalition led by the U.S. Chamber of Commerce is launching a multi-million dollar television ad drive to kill the Democratic measures.  The ads will start on national cable tomorrow and are expected to focus on 20 to 25 key districts, say two sources familiar with the new ad blitz.

Employers for A Healthy Economy -- which includes the National Association of Manufacturers and the National Retail Federation--and another coalition that the chamber also underwrote, previously ran over $100 million in ads to kill or seriously weaken health care reform bills in the House and the Senate, both of which ultimately passed.

The new ads will run for 10 days and were developed by National Media, a firm co-founded by long-time Republican ad maven Alex Castellanos. One source described the ads as "the closing argument" by the chamber and its allies to kill the bill and try to convince Congress to "start over," a message that business and GOP leaders have been trying for months to hammer home to the public and members of Congress.

The White House and Democratic leaders are now focused on getting the House to adopt the less ambitious and less costly measure that the Senate passed. The chamber and several other business and conservative groups have targeted a few dozen Blue Dog Democrats who are deemed swing votes. The health care bill narrowly passed the House last fall by five votes and was opposed by a number of Blue Dogs who are now getting enormous pressure from lobbyist on both sides of the issue as well as the White house and political leaders in both parties.

In a related move, a grassroots coalition called Start Over that includes many of the same trade groups, has commissioned public opinion polls on the health care issue. The results expected later this week.