[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/07/29/art.rumors.cnn.jpg caption="A new AFL-CIO mailer seeks to dispel continued false rumors about Obama."]
(CNN) - The nation's largest labor conglomerate says it's set to launch a major effort Tuesday to dispel ongoing rumors surrounding Barack Obama that continue to percolate more than 18 months after the Illinois senator launched his White House bid.
The organization is set to send out mailers to more than 600,000 union homes in crucial battleground states - including Ohio, Michigan, Pennsylvania, and Wisconsin - that directly address the false rumors that he is not a Christian, refuses to wear a flag pin on his lapel, and was not sworn into the Senate on the Bible.
It also beats back claims the Democratic presidential candidate was not born in America and refuses to put his hand on his heart during the Pledge of Allegiance. (view the mailer [PDF])
A majority of AFL-CIO's membership is considered part of the working-class demographic - the key voting bloc that overwhelmingly supported Hillary Clinton in the prolonged Democratic primary race and is likely to play a key role in the battleground states this November.
Watch: Obama battles rumors online
The AFL-CIO is also sending out a second mailer that features testimonials for union workers in support of Obama's policies on job creation, health care reform, and worker's rights. (View the second mailer [PDF])
"The mailers are the leading edge of a massive campaign in August to clearly define Sen. Obama among millions of union voters and to contrast the policies and plans of Sen. Obama with those of Sen. [John] McCain," AFL-CIO spokesman Steve Smith said.
That massive campaign will include a large-scale mobilization effort in 24 states, targeting 13 million union voters. The organization will also deliver more than 1 million fliers touting Obama's record at work sites across the country in August.